Jaiku (http://www.jaiku.com) is emerging as the preferred presence sharing application.
They have the best feature set, says Leo Laporte. Leo was among the earlier evangelists of Twitter, who is leading the army of users switching to Jaiku. According to Leo, "In truth, it (Jaiku) offers a much richer set of features than Twitter."
Discussion (2)
The more sites that (sensibly) support OpenID the better!
Leo' quote aside, which it is hard not to agree with, the main reason for Leo's departure from Twitter was the TWiT-like name. :-)