Yes, Google can read Flash content. When you say 'hide' the content do you mean you plan to do something like stuff the Flash file with keywords?
Please do explain.. I have two ideas about your question. 1. You're asking if you can hide text inside the flash, 2. You're asking if you can hide text behind the flash animation. Which is which???
I was also wondering about hiding text- not behind flash but behind a regular image. does that actually work?