Rolling out IMAP support for gmail made my life better. I know it came out a while ago, but i finally got around to getting it set up. I got my PC and my laptop outlook clients synced up with gmail effortlessly. I create a folder on outlook and it adds a label to my gmail. I flag a message in outlook and the message gets starred in gmail. sweet!
more info
http://mail.google.com/support/bin/answer.py?hl=en&answer=75725