I have a Canon S3 (had and S2...sent the S5 to my dad, as they are wayy harder to hack), and have been using the CHDK mods on it. WOW! most of the Canon Powershot series can be mod in this way... check it out!
http://chdk.wikia.com/wiki/CHDK -up to 65 sec exposures.
-script writing (motion trigger, stereo imaging, etc)
-more f-stopz!!
...just look at the damn wiki page. . . .
(edit, and RAW!!@!!)