Sweet. In the current beta/demo going, you can go to options and set up a twitter account, and the game will tweet your progress when a certain something happens. First, you can input your twitter username and password, and then go to events, and select what sort of thing you want to tweet. There is a few options here you can turn on or off, these are:

When connecting to multiplayer
When a cinema file is uploaded
When a chapter is complete
When earning multiplayer money
When earning trophies
When reaching a level milestone

I think this is a great idea, people will see the achievements you have completed without you actually doing it. I can go to twitter now, and search for #UNCHARTED2 and see what people are up to, how much money they have earnt in a nice and clean format. I have put "on" on two of the options above, when reaching a level milestone and when earning multiplayer money. So far it has tweeted my progress twice, and im not sure what time it tweets at, maybe when you log off or at a certain time, but I can't really tell for sure.

At least it is not updating every second, like thetimesplitter earned $1000, then another tweet saying i earned another $1000 playing multiplayer, it lumps it together which is good to avoid spam. This is a nicely included feature in Uncharted 2. Hope there are more little great things like this.

 PS you can view my twitter by hitting the twitter link to the left there, or by going to twitter.com/thetimesplitter