hey I found this and wanted to share it with you bc your 'shutter lag' has nothing to do with your megapixels...
Low Shutter Lag: A big problem with some digital camera models, especially P&S's, is "shutter lag". That's the time between when you press the shutter and when the camera actually makes the picture. Several things happen when you press the shutter button: pressing it halfway starts the focussing process and sets the exposure; then pressing it all the way "trips the shutter" and the picture is made. The camera can delay too much for your taste at each (or all) these stages but the most annoying is the last stage when, after you've set the focus and exposure, and recomposed your shot, and you finally press the shutter at the exact right moment, and - long long pause - the picture is made. Long shutter lags can be a disaster when filming nearly any subject. To paraphrase Mark Twain: the difference between the right picture and almost the right picture is the difference between lightning and a lightning bug.
Check the camera specs for shutter lag though they'll be only minimally useful, if you find them at all. Manufacturers are not very forthcoming with these numbers and there are no real standardized methods to measure shutter lag either. Dig through the internet for current information anyway. A good source of photo equipment information is
http://www.dpreview.com/ Also, you can judge for yourself by test firing the cameras at the photo store. Make sure to set the ISO to 400 or higher and pre-focus on something first. Your tests will be totally subjective but you'll get a real world idea of whether that particular model has a low enough shutter lag for you.