Ben is compact flash.

I don't mean the storage media.

I think that the Canon Speedlite 580EX II is the best thing I have purchased for my photography hobby.  It is an extremely configurable and powerful flash that works with my EOS Digital SLRs and my Powershot G10 with ETTL-II (electronic, through the lens).  However with all this power the 580EX II is really huge.  It's hard to carry around and looks ridiculous mounted on my G10's hotshoe.

I have been researching a more compact solution and found the ideal one, the Speedlite 270EX.  It provides enough power to be used as a fill flash for the SLRs but also is very small, the best part of it is the ability to use the flash to bounce light (when the camera is held in landscape mode)

Check it out on my Powershot G10!