Rather than just have this icon journal be for posting my icons, I figured I'd throw a few tutorials in there as well. I'm sure some of the stuff I'll be telling you guys how to do has been posted before, but I'm going to explain it anyways, haha. It makes me feel useful.
I added a few things on top of the torn edges including a gradient as well as another image, but you get the basic idea of the look of torn edges.
This tutorial is for Photoshop and is for the torn edges look.
1. First, take your 100x100 image of the underlying picture that you want.
2. Create a new layer over this image and fill it with the color of the "ripped page" that you would like.
3. Take the Lasso Tool and make jagged line however you want the torn paper to look. For the icon above, I just did a strip across the image, but you could do the torn images as a border or whatever you like. Complete the circle by continuing outside of the object until you join with the beginning and the area is selected.
4. Hit delete. If you drew the lasso tool around the part of the image that you wanted to keep, just right click and hit "select inverse", then hit delete.
5. Hit control+A to select the whole layer. Hit the control button and click on the layer in the Palette that has Layers, Channels, and Paths. This should select the layer. Then go up to Select > Modify > Contract.
6. Contract 3 or so pixels.
7. Now right click on the image and select inverse.
8. Filter > Noise > Add Noise. Play around with the level of noise until you get a torn look that you're happy with.
9. Voila! Flatten your image, save your jpg and there's your icon!
If any of this was unclear or you still have questions, please let me know! I hope this helped some of you guys.