For the noise in Digital camera, is talking about the unexpected colour or white spots shown on the picture especically in dark enviroment. You may find and compare easily when shooting in dark enviroment with high ISO setting (eg. ISO400 or ISO800, even 1600) but not turn on the flash. An example just like my small picture shown next to my user name over there.
Meanwhile, the price of Cannon 850IS will be a bit lower than the listed $3080. Go for few shops and ask the actual discount. FYI, my sister in law just bought one 850IS at $2780 last month. The package comes with 2G HCSD card, 1 extra battery (3rd party brand), carrying case, LCD protective sheet and a mini-tripod.