I don't use a lot of extra add-ons, haxies or monitors, but I run Little Snitch continuously, no problems, under 10.2 - 10.2.8. I like it.
It often flags interesting results (apps you wouldn't expect to phone home - or anywhere else.) It tells you the app, the IP it's calling, and the port it's calling. It lets you authorize a single connection, or set up permanent rules about which apps can/can't make connections to which ports and even to which IPs if you choose. Once you get the first alert for each app and tell it your mood, it sits unobtrusively in the background. I think it's very nicely done, and $25 well spent.