I don't recall any significant instances of changing my opinions because of a forum debate. This is probably because I don't start at extremist positions to begin with, and try a lot harder than most of the common chaff posters you'll find to establish a common ground to debate from.
What I have learned is that people know jack-shit about what constitutes a good source for information. I was taught all throughout college how to critically analyze a piece of writing and evaluate the viability of a source, but I'm consistently appalled at the claims I've seen thrown around because of some MSNBC article or CNN poll.
Maybe I've become more Moderate, but I think that occurs from simple exposure to a large number of others' opinions. I wasn't particularly Super-Liberal to begin with, though the current political climate's "Conservatives" would label me a Fascist-humping limp-wristed Neo-Liberal-Socialist.
College professors have done more to change my opinions than the internet ever has. Whether it's about religion, sexuality, art, science, history, or anything else I can think of. When I had to actually study the topics in-depth, my views changed. Now I try to do so whenever a debate on the forum comes up so I can educate myself against obviously false counter-arguments, and if evidence comes up that denies my argument validity - I accept it.
Being wrong is sometimes the best thing that can happen.
