Alternatives to TiK?

Another member of Clan Anonymous Coward asks: "What alternitives are there to TiK? If I remember correctly ICQ is all reverse engineered on Linux which doesn't really make it much better than our current fight with TiK. There is always Talk and IRC but none of those have a centralized location service the way TiK does. I like TiK because you don't have to deal with multiple networks (IRC) and you don't have to deal with figureing out where some dynamic ip went (Talk). What other options exist. "