i was on the xbox.com site when i saw a question posted "How to connect to Xbox Live with Comcast". So, i was wondering, is it free if i just connect online with Comcast or do i still have to pay monthly?

Erm, Live was never free. You pay a subscription fee.

All details are at www.xbox.com/live

There are free trial periods but as Memphis said you'll have to pay a subscription fee beyond that.

yeah, theres always been a monthy/annual fee, unless you were a beta tester up until it was launched.