I have to answer this question a great deal in my digital photography classes I teach. I noticed that Digital Photography Review has done a great article on this topic. Visit them here

http://www.dpreview.com/news/0210/02100402sensorsizes.asp

There is a convienent chart at the bottom of the article that list all the common sizes.

Jeff

Many thanks, Jeff...

DP Review is such an informative site, my favorite of all the digicam resource/review sites out there. I think it's interesting that Canon has introduced a CMOS chip with the "same size image plane as 35mm film" on the new 11-megapixel EOS-1DS.

Megapixel at megaprice, at least outside of the US. You're looking at approx AUD$18000 for one of these babies. At least they finally realised more realistic focal lengths for digital cameras.