Here's how you get Jedi Academy and Jedi Outcast to work in widescreen. I had nothing to do with this mod, I'm just posting this here to help.
Here is the link, instructions are in Ruku's third post, btw. Enjoy:
Remember, the files you will need to edit for this to work in Jedi Outcast will be jk2config for single player, and jk2mpconfig for multiplayer.
Another quick note: some loading screens might not show up as they are not supported in a widescreen resolution, so be prepared. But I've only experienced this in Outcast. Instead of a loading screen, you get a screen full of white, as I said though, this only happens in Outcast as far as I can tell.