This isn't directly related to my SF project, it's related to another script project I'm working on. Woudl it be possible to have a flashback within a flashback. My storyline is set up sort of like "The Princess Bride" (except the book story is the equivalent to the larger flashback).

I experimented really quick...and yeah, it's possible to remember when you remembered something. But it hurts my head. :P

If the majority of the book is a flashback, then I don't see a problem with another, smaller (relatively speaking) flashback. Though with short flashbacks, a flashback inside of it, could get confusing.

Does the word flashback sound funny to anyone now?

I would agree with you. In Princess Bride, which is almost entirely a flashback, if they'd segued off into a scene of how Westley became Dread Pirate Roberts, it would be fine - it's a storybook being read, and books often have out-of-nowhere asides.

If it's a character having a flashback, and then there's a flashback inside that... well, the only ways I can think of to pull that off would have their usefulness more in getting the reader/audience confused and off-balance than actually relaying information. I'm thinking Run Lola Run, with the flash-forwards. Amelie also does it(?) - flashing back to when she was a kid, and then moving around in that timeframe.

It'll probably come off disjointed, but that's a useful tool, right?