theseus’s posterous

The repository system is a great strength of open-source operating systems, but some people want the latest-and-greatest of a particular application while keeping the core system unchanged. There is also the situation where non-free applications aren't available from within the standard repositories. In these two cases, adding outside repos can help you get the functionality you want. I've done some homework for you and here are the "Extra Repositories for Ubuntu 8.10 You Might Want." Simply open up
System > Administration > Software Sources 
and add the repository lines listed below as a third-party repository.

Here are your repositories!

Medibuntu

Medibuntu is the best way to get some video and audio playback capability that isn't included in Ubuntu 8.10 for patent reasons. If you live in a regioon which doesn't support these patents, you can go ahead and get them. Popular packages include:

• Acrobat Reader
• Firmware for the ALSA sound system
• Google Earth
• DVD decryption
• MPlayer / MEncoder
• Non-free codecs and
  
• Skype
  

Add this line to Software Sources:
When you are finished, install the medibuntu-keyring and app-install-data-medibuntu packages.

Wine

Ubuntu 8.10 ships with Wine 1.0, but the development version is able to run many more Windows programs. You can get the latest version from the Wine repository.

Add this line to Software Sources:

When you are finished, install the wine package.

OO.o3

OpenOffice.org 3.0 just missed the cut-off for Intrepid. If you want the additional functionality of 3.0, you'll need to add the PPA for the OO.o team.

Add this line to Software Sources:

When you are finished, upgrade and everything should be fine.

Opera

While Firefox is a great browser, some people just prefer Opera. Opera makes it easy for Debian-based OSes.

Add this line to Software Sources:
deb http://deb.opera.com/opera/ stable non-freeWhen you are finished, install the opera package.

Banshee

Banshee is an audio and video manager which is seeinging extremely rapid development. New features are added every month.

Add this line to Software Sources:

When you are finished, install the banshee package.

VideoLAN Client (VLC)

While I prefer Totem, many people, especially those recently from Windows, prefer the media player they've known and loved for years. VLC is in the repositories, but keeping up with recent versions means adding this line to Software Sources:
When you are finished, just install the vlc package. You can also get apt-cache-ng from this repo.

Boxee

Boxee is an amazing media center (derived from XMBC) that runs on OS X and Linux, and it does just about everything you could imagine. Right now, it's alpha, and you'll have to sign up on the Boxee registration page in order to use the software.

Add this line to Software Sources:

When you are finished, just install the boxee package.

Elisa

If you don't need all the craziness of Boxee and just want a simple media center, take a look at Fluendo's Elisa. It uses GStreamer, already the default A/V decoder on Ubuntu, so it won't add a lot of weight to your installation.

Add this line to Software Sources:

When you are finished, install the elisa package and update your computer.

Netbook Remix

One of the most innovative things to come out of the Ubuntu camp is the neetbook remix interface. Want to try it out?

Add this line to Software Sources:

Then follow the detailed instructions on how to get it running.

Gnome Do

This launcher amazes everyone who tries it. These days, it even comes with an optional dock. Although I don't use it daily, I think everyone should give it a shot.

Add this line to Software Sources:

When you are finished, install the gnome-do package.

Deluge

Intrepid comes with the Transmission BitTorrent client installed, and Tranmission is fine, but Deluge is a full-featured client which rivals and may now beat the Azureus cum Vuze client that so many people swore by for years. As a bonus, Deluge is a GTK2 application, so it doesn't use up 50% of your CPU while running several torrents.
Deluge has a wide-array of features, including:

• Web UI
• BitTorrent Protocol Encryption
• Mainline DHT
• Local Peer Discovery (aka LSD)
• FAST protocol extension
• µTorrent Peer Exchange
• UPnP and NAT-PMP
• Proxy support
• Private Torrents
• Global and per-torrent speed limits
• Password protection

Add this line to Software Sources:

When you are finished, install the deluge package.

Google Gadget

Google used to host a repo itself, but that went away and we are just left with a PPA for Google Gadgets. It's for Hardy (8.04), but there doesn't appear to be a problem with running it on Intrepid. Caveat emptor.

Add this line to Software Sources:

When you are finished, install the google-gadgets package.

Mythbuntu

If you installed Mythbuntu and want to keep up with the latest release of MythTV, including all kinds of extra plug-ins:

• mytharchive create and burn DVD's from MythTV - binary file

• mytharchive-data create and burn DVD's from MythTV - data files

• mythcontrols External controls for MythTV

• mythflix netflix module for MythTV

• mythgallery Image gallery/slideshow add-on module for MythTV

• mythgame Emulator & PC Game frontend module for MythTV

• mythmovies Find nearby movies and cinema listings

• mythmusic Music add-on module for MythTV

• mythnews An RSS feed news reader module for MythTV

• mythphone a phone and videophone module for MythTV

• mythplugins Metapackage for MythTV plugins

• mythvideo A generic video player frontend module for MythTV

• mythweather Weather add-on module for MythTV

• mythweb Web interface add-on module for MythTV

• mythzoneminder view status and display footage recorded with zoneminder 

 Add this line to Software Sources:
When you are finished, update your installation.

Compiz

Compiz Fusion comes standard on Ubuntu, but you might want to keep up with the mosst current version to have all that extra BLING.

Add this line to Software Sources:

When you are finished, update your installation.

Miro

"Miro is a free HD video player." Somehow, the website's description falls so short that I don't know how Miro is as successful as it is. They must be going understated. It aggregates a browser, an RSS reader, a bittorent client, and a video player. Want TV on your computer? Get miro.

Add this line to Software Sources:

When you are finished, install the miro package.

Shutter

Vadi recommends Shutter (recently renamed from GScrot), an extremely capable screenshot tool. Features include:

• take a screenshot of your complete desktop, a rectangular area or capture a website
• take screenshot directly or with a specified delay time
• save the screenshots to a specified directory and name them in a convenient way
  (using special wild-cards)
• Shutter is fully integrated into the Gnome Desktop (TrayIcon etc.)
• generate thumbnails directly when you are taking a screenshot and set a size level in %
• Shutter session collection
  
  • keep track of all screenshots during session
  • copy screeners to clipboard
  • print screenshots
  • delete screenshots
  • rename your file
• upload your files directly to Image-Hosters (e.g. http://ubuntu-pics.de), retrieve all the needed links and share them with others
• edit your screenshots directly using the embedded drawing tool.

Add this line to Software Sources:
deb http://ppa.launchpad.net/shutter/ppa/ubuntu intrepid main
When you are finished, install the shutter package.

Other Possibilities

Commenters recommend AppSpot and the Ubuntu PPA search to find repositories for applications you may need. AppSpot even has a grouping of recent searches to spur your imagination.

Keys

You'll have some package manager complaints about keys if you're not careful. Import these keys to get rid of the warnings. Allaun recommends using the NO_PUBKEY value (e.g. C5E6A5ED249AD24C) to add the key with the following command.

OpenOffice - http://keyserver.ubuntu.com:11371/pks/lookup?op=get&search=0x60D11217247D1CFF

Gnome-DO - http://keyserver.ubuntu.com:11371/pks/lookup?op=get&search=0x28A8205077558DD0

Deluge - http://keyserver.ubuntu.com:11371/pks/lookup?op=get&search=0xC5E6A5ED249AD24C

Google - https://dl-ssl.google.com/linux/linux_signing_key.pub

WineHQ - http://wine.budgetdedicated.com/apt/Scott%20Ritchie.gpg