Got a Canon point and shoot? You can enhance its capabilities with CHDK

Canon Hackers Development Kit.

http://chdk.wikia.com/wiki/CHDK

I have a Canon S90 P&S and just tried out the CHDK firmware upgrade for it, went from 15 seconds maximum shutter to basically unlimited, I've taken 20 minute exposures already.

CHDK adds the ability to script your exposures to automatically do time lapse photography, focus bracketing and HDR bracketing. Also adds the ability to use a simple USB remote trigger for your camera and to synchronize two identical Canon P&S cameras for taking stereo photographs and adds a motion detection trigger that's fast enough to capture lightning. One more thing, CHDK allows the use of RAW files on many Canon P&S cameras that don't have that as part of the stock firmware.

http://chdk.wikia.com/wiki/CHDK_in_Brief

http://chdk.wikia.com/wiki/CHDK_for_Dummies

http://chdk.wikia.com/wiki/FAQ

CHDK also allows very high shutter speeds, up to 1/60,000 of a second, here's some interesting water splash photos taken at very high shutter speeds with a hacked Canon.

http://chdk.wikia.com/wiki/Samples:_High-Speed_Shutter_%26_Flash-Sync



And here's someone using the motion detection trigger function to capture images of lightning.

http://www.dexterityunlimited.com/2012/04/25/thunderstruck-lightning-photography-with-chdk/