I'm really surprised at the lack of information for good data access strategies in Flex.

I have a Flex application that will use Coldfusion as the back end, but I'd like it to easily adapt to a web service that could be written in PHP, Java, ASP, etc. I can't find any good resources that demonstrate a best practices for this kind of flexibility. There's a lot of talent out there so I know someone has already tackled this problem.