To go along with 5eyes tutorila on prior art tutorial, I found this article that lets those of us that didn't have a clue about this stuff before learn about patents and the process of making a claim etc...
http://www.hightech-iplaw.com/leswibar2003.pdf
From what I have read, there are three options here:
a) Everybody settles and pays the fees
b) We find prior art and get the patent dissolved
c) The courts through the patent out
Option (b) and (c) are spendy to prove and take time. According to that article, even if we find Prior Art it will cost a lot of money.
Another thing in that article that I found helpful is that is says it is ok to ask for donations to fight a patent claim, so the idea of putting a link on your sites asking for paypal donations is not such a bad idea after all.
Don't say anything bad against the patent holder or they can sue your asses
Flow