I don't see how using UDP makes anything more anonymous. The packets still come from your IP, with your IP stamped all over it. They still have a port number. They contain the same data an equivalent TCP packet would. Just because fewer people (and monitoring tools) are aware of UDP... it's used less often because it's not reliable like TCP. Mostly used for games and streaming media where losing a few packets here and there is not a big deal. Once you know what you're looking for, it's just as easy to capture and reconstruct a UDP stream as it is to sniff a TCP connection. And TCP works better through firewalls too.
I'd agree with the FreeNet guy. Unless you're using encrypted connections a'la FreeNet/Waste, or some sort of universal forwarding mechanism (aka plausible deniability), you have nothing resembling anonymity, and you're just fooling yourself. Probably your best bet is to blend in with the masses so you don't get singled out in a lawsuit.
And, uh, right back atchya, US!
