Canon makes some very small digital cameras but it's actually a little difficult to tell which is really the smallest canon digital camera. The stats below show Canon's two tiniest ultra compact digital cameras.
PowerShot SD1100 IS
3.42 x 2.16 x 0.87 in./86.8 x 54.8 x 22.0mm
Approx. 4.41 oz./125g (camera body only)
PowerShot SD770 IS
3.39 x 2.13 x 0.80 in./86.0 x 54.0 x 20.4mm
Approx. 4.59 oz./130g (camera body only)
As you can see, you have the SD1100 IS which is the lightest canon compact. And you have the SD770 IS which is the shortest in length. The SD770 IS is shorter by .03 inches or .8 mm. Certainly that is not a big difference in size. And on the other side of the coin, the SD1100 IS weight less than the SD770 IS by .18 ounces or 5 grams. Not a hell of a big difference either. I hardly think either of these cameras would feel any different in one's pocket.
The SD1100 IS is priced at $149 at Ritz Camera. The PowerShot SD770 IS is $159 at Amazon and $149 some other places. So for all intents and purposes, the price is the same. So is there much difference between these two little digitals?
Shutter speeds are the same at 15-1/1500 sec. Flash range is the same at up to 11 ft. The 770 can use the SDHC memory card where the other cannot. But they both handle SD & MMC. The SD1100 IS is nicely designed with a stylish colors available. The other compact digital is apparently only available in traditional silver. The SD1100 also features a pinhole viewfinder for those who want an option to the LCD screen.
Reviews seem to favor the SD1100 for picture and video quality. Although the raw stats don't yield much discernible differences, but it has the edge in design and look and feel. Price points are similar on these two ultra compact digitals so if your shopping give the canon SD1100 IS a try for sure. Certainly it can't hurt to compare the two but if you're undecided, general recommendations favor the SD1100. Regardless you will have a camera that fits comfortably in your pocket, purse or backpack. As new models are released I will update this topic as needed. Digital cameras are being released all the time as you know!