You like the idea of Google Talk, but you do not want a Gmail account -- well, you were out of luck until tonight when they released version 18.104.22.168. Now anyone can sign up for the service by getting a Google account.
Simply download Google Talk and log in with your new account. There are some features that you will only get if you have a Gmail account still -- like chat history and mail notifications. It would be nice to see a built-in chat history feature in Google Talk -- and I'm sure enough people will complain about this to make it a worthwhile addition.
The product has come such a long way since its launch, and so I am looking forward to see how it improves over the next few years. Maybe we're getting close to video conferencing, skins, or even IM to landline functionality -- keep your eyes peeled.