Hi Ben,
here are two links on PCB-Designers:
EAGLE:
It's freeware (limitied board area and two signal layers)
I think that's enough for small projects
http://www.cadsoft.de/freeware.htm
Target 2001! V8 Discover
It's also freeware (limited board area and Database is restricted
to 3000 elements)
http://www.ibfriedrich.de/

Christian