Canon PowerShot G12 Black 10MP Digital Camera $370 at Adorama

Nice as 2ndary camera for DSL.owner. A little slow but wonderful picture quality..

was just looking to buy the g12, p7100 or the s100. Anybody with some personal recommendations?

I had the G11 and was disappointed with it. It was very slow with live action photos such as grandkids' games. Otherwise it was a good camera with a lot of manual settings. Got a Nikon D5100 and there is no comparison.

I have a G12 and I love it. I don't have any issues with its speed. And if you leave it in "fast shutter" mode, it takes very fast pictures.

#2 : I think they are all good cameras It really depends how you want to use it.
G12 and P7100 basically are more advanced Point&Shoot Camera. They were design between DSLR and Point&Shoot Camera. So they have hot shoe for external flash, more dial for more easy control/adjustment/manual setting. So if you want to learn DSLR skill. P7100 and G12 can be a good starting point. And many DSLR owner own them as 2ndary camera when they are lazy to set up DSLR for quick shoot.
I played aroung G12 for a week ( borrow from friends)- it gives great quality photo but I feel a little slow on auto focus speed. But that might be common problem for point& shoot camera.
http://www.dpreview.com/reviews/studiocompare.asp#baseDir=%2Freviews_data&cameraDataSubdir=boxshot&indexFileName=boxshotindex.xml&presetsFileName=boxshotpresets.xml&showDescriptions=false&headerTitle=Studio%20scene&headerSubTitle=Standard%20studio%20scene%20comparison&masterCamera=nikon_cpp7100&masterSample=dscn9951&slotsCount=4&slot0Camera=nikon_cpp7100&slot0Sample=dscn9951&slot0DisableCameraSelection=true&slot0DisableSampleSelection=true&slot0LinkWithMaster=true&slot1Camera=canon_g12&slot1Sample=img_1078&slot2Camera=canon_s100&slot2Sample=img_0091&slot3Camera=canon_g1x&slot3Sample=img_0003&x=-0.39385107816711584&y=0.07154924910792881&extraCameraCount=0
Check the above link for dpreview.com studio shoot and compare the photo quality yourself. I think clearly the quality wise Canon beats Nikon to me. Picture is always the 1st priority - always.
But if you just want a compact and easy operate camera then S100 can be a better choice.
If U are alreay Nikon user and have flash/accessory available. Or you prefer extra zoom than Canon and you like the extra buidin In-camera panoramas HDR.. - Nikon can be your better choice . ( But remember these are just basic function and not really preferct)

if you already have a DSLR, why get another camera like a DSLR? I have the S95 (older version of the S100) and it is a great camera.

1. It is pocketable
2. It has a fast lens (f2.0)
3. It does HD video

Perfect for those quick shots when the dslr might be slower to setup.

I own a DSLR but always have G series ( since G5 era) as 2ndary. Besides the picture quality I also like the flip screen , 3 manual dials and also view finder. specially G series just give more convenience than other small point&shoot. in case you want some quick adjustment.. When you get used to shoot DSL- you should know full auto mode is not really idea setting. If you read the post here long enough you will know someone even complain the mode setting on 60D( like sports, landscape.. build in mode) pretty sucks. The S100 definitely can also run manual mode but it won't be as convenient as G12 with 3 dials. And I don't think the per-defined mode is enough for me. But if you going to shoot auto mode all the time- maybe S100 is the best of the 3 you mentioned.
This is just my personal thought ...