Let the hive mind of Engadget get that for you.
"We need a digital camera that can be switched on and fire off that first shot fast. It's not a commonly tracked statistic on any review site, and nobody seems to have this information for every camera. We were hoping other readers could inform us as to what small digital cameras can fire off their first pics in under a second (ideally under half a second). It needs to be small, but mostly, just really quick in operation. Thanks!"
Puppy Linux is optimized to minimize writes to the CF card and has an installer that recognizes and cleanly installs to a CF card in an IDE adapter. Writing this on a throwaway Dell inspiron 4000 using such an adapter, a Rosewill 256 Mb CF card and Pup 2.16.1. Totally silent, even more robust. Give it a go..
Developer link is http://www.puppylinux.com/news/