I added info on how to test the F3 Polyfuse to the troubleshooting page:
http://elinux.org/R-Pi_Troubleshooting# ... r_problems
If any of you could just give it a quick once over I would really appreciate it. Feel free to make any needed changes there or tell me here and I will update it.
2 things I was not 100% sure about:
What voltage drop across F3 should be considered probamatic, I put in 0.03v - 0.10v as about normal
How long a polyfuse takes to "reset" if it has been tripped, I said about 24 hours.