I am going to install plugins for mp3 and other codecs on Ubuntu 7.10, but I don't have any internet connection on my laptop, so I can't use add/remove to install, how can I find the package to install it manually?

I'm a linux noob myself but I think they'd be under Synaptic Package Manager.

I believe if you go to packages.ubuntu.com/gutsy you can find a package under multimedia called libmp3lame. The only problem with this is downloading all the dependencies, and the dependencies of the dependencies. There is no automated way (that i know of) to download all dependencies without using a program like apt-get. I struggled with this exact problem with ndiswrapper, and the computer that i used to do all the downloading on was 4 miles away. I didn't get dependencies, and had to drive back and forth to the downloading computer. Do you have another ubuntu box that you can use as a downloading computer, because there might be a way to just download all the dependencies through apt-get.