Fairly interesting development from Google - I've noticed that they now spider (and display) thread information from forum results. This is fairly useful if you're searching for something specific and want to find a thread that has been posted recently, or contains a large discussion about a particular subject.

Here's an example of how it looks:

It seems to work with vBulletin and phpBB from a quick few searches, quite cool knowing that Google goes into this sort of depth when returning results!