I was asked how to detect if the flash plugin is installed. I found some pretty good info adobe puts out on this.

There are several useful articles here

http://www.adobe.com/support/flash/detection.html

This one is particularly applicable to detecting if the flash player is installed.

http://www.adobe.com/cfusion/knowledgebase/index.cfm?id=tn_14526

I’m glad they have this information because although most browsers do have flash installed developers should still play nice with those who don’t and they should espicially make sure that the user has the correct version for any newer features of flash that they are using.