I wrote this article for the Flex 2.0 release.
It is a good intro on how you can move data between Coldfusion 7.02 CFCs and Flex 2.0 using Web Services or Remote Object calls.

My co-worker, Lin Lin, blogged a good follow up to this article that expands up on the configuration and steps necessary to access cfcs on your Coldfusion server from a flex app on a separate server.