EAGLE has a crappy lite version, there're also things such as ExpressPCB and ExpressSCH.
There are also:
FreePCB
TinyCAD (though this may just be schematics, iunno)
ZenitPCB
There're more, Google around.
If you're an engineering student look around at what your school offers program-wise. Most engineering schools give you ProE or something similar, and that has a PCB/Schematic editor I believe.