First of all, I realize that the guide I used was a few years old, but I looked around. It was the most recent one I could find.
I followed the instructions to the letter. Now when I try to start the emulator, I get the following message:
anthony@anthony-1010:/$ epsxe
./epsxe: error while loading shared libraries: cannot open shared object file: No such file or directory
I imagine that this is because LibGTK has updated to version 2.0 since the guide was written.

Got any ideas?