Jen asks:

Do you know of a good flash detection script available, for use with flash forms? Most of the ones we have tried only detect when flash player is not installed at all. If the client system has an old version of flash there isn't an error or prompt to update - just a blank screen.

I can think of two excellent resources. The first is straight from Adobe: Flash Player Detection Kit. I've used this on a project before and it works like a charm. If you just need to check Flash players, I'd use this.

If you want to do more advanced checking, you want to consider Browserhawk. It can check everything. Seriously. It can probably tell you what the coder had for breakfast when he or she compiled your browser. It isn't cheap, but it works like a charm.