Homebrew PCBs

Haven't tried it, but $39 for the personal version ain't bad.  It
seems to include some PIC emulators, which takes it a step beyond
typical SPICE programs.

If you don't need the PIC emulation, then I recommend LTSpice which is
reasonably fast, easy to use, and free (as in "free beer"). 
http://www.linear.com/designtools/softwareRegistration.jsp .  There is
a very active user group at http://groups.yahoo.com/group/LTspice .

Cheers,
- Jan