LW for Linux has a built-in mp3 and audio player, but it does not have a built-in video

If you want a video player I would suggest MPlayer or Xine (I prefer Xine myself).

MPLayer can be found here:
http://www.mplayerhq.hu/homepage/design7/news.html

Xine can be found here:
http://www.xinehq.de/

What distrobution of Linux do you use? If you use Fedora Core 3 there are some "rpms" (a file sort of like "exe" for RedHat based Linux OSes) for both Xine and MPlayer here:
http://heidelberg.freshrpms.net/rpm.html?id=903

Just scroll down the left side and look for MPlayer or Xine.

If you get the RPMs the install is quite easy:
If you get any errors saying that a file could not be found search for it here:
http://rpm.pbone.net/

Use the "Advanced Search" option and make sure your distro is the only one checked off.

PS-If you do go with Xine....go back to the MPlayer site and download their "Essentials" package.

Then as root do the following commands:
And that should do it.

I would try to use Xine at all costs because it is easier to manage. Every time that "essentials" pack is updated it usually involves a re-install of MPlayer (that is, if you use MPlayer). Whereas with Xine you just extract the new essentials to that /usr/lib/win32 directory and you are all set.

Also if you do use Xine you will need to edit an option in LW, so that it knows to use Xine (it looks for MPlayer by default).
To do so:
1. Open LimeWire
2. Go to Tools
3. Go to Options
4. Go to "Helper Apps"
5. In the "Video Options" portion on the right you will see a text field with "mplayer" in it. Change "mplayer" to "xine"