Are you sure about that? From what quipper8 said above, it doesn't sound like it's guaranteed that the number will be yours forever. Which means that, like AIM, you might only be able to use it for a little while, but it's not known exactly how long you can use it (I've seen the AIM number still work after a few days of inactivity). If that's the case, then it would seem to be equal between the two services.

The Google number at least looks like a real phone number, though. But I'm not sure if that's a good thing or a bad thing (someone might try to actually call it -- I wonder what sort of confusion that might cause).

Does that only work if you're using gmail? I know Google Talk will queue your messages in your Chats folder on gmail, if you're not online... but I don't know if you can get those without logging into Gmail.

I didn't, in my test, notice it being significantly less obnoxious.