Google's Gmail Labshas just rolled out a useful, but mildly creepy feature that gives you suggestions on who you should e-mail based on previous conversations. So, if you've had threads going with a group of people, it will recommend some of those folks once you've added at least two addresses in the recipients field. Best part is, they don't even have to be in a group of contacts you've created in Gmail's contacts manager.

I got this to work to an almost uncanny level. It handles things li...