iPhoto for iPad is a fantastic photo editing app with a ton of multitouch gesture support. When editing and looking through your photos within the app on your iPad, all it takes is a bit of learning to get these gestures down and make your time with iPhoto just that much more productive and fun.
First up, tap into a photo album in iPhoto for iPad, and drag the little three horizontal lines widget at the top of the thumbnail column. Drag to the right to get up to four columns, and to the left to reduce the number to one. To make it disappear entirely, drag any photo in the list to the left. Bring it back with a swipe from the left bezel to the right. Of course, you can tap the grid icon there to show and hide the thumbnail viewer.
Next, tap and hold on up to 12 different photos in the left column browser to add them to a virtual light table on the right. You can tap any of the photos in the light table to zoom in, and then tap off of them to zoom back to the light table view. You can also swipe through individual photos in that right hand space as well.
Tap into a photo and then tap with two fingers in the photo itself. The magnification Loupe will show up. drag it around the photo to see up-close details, and rotate two fingers on the screen to change the magnification from 1X to 2X or even 3X zoom. Tap off of the Loupe to dismiss it.
Hopefully, this gives you a few more gestures to play with in iPhoto for iPad, and makes your photo editing and browsing more productive and useful.