Easy to make and requires only one bought item - everything else can be found around your house.
The "lens" does no damage to the camera or lens. I designed this with that thought in mind as I loathe scratches or dings on my gadgets.
Step 1: Materials
1 (One) Flip Mino Camera
1 (One) Film Canister
1 (One) Two Rubber Bands
1 (One) Security Door Viewer (Peep-hole thing found in apartments)
2 (One) Rubber Bands
1 (One) Drill Bit (size depends on the size of the door viewer
1 (One) Cordless Drill
I found most of these items around my house. The only item I had to buy was the security door viewer which I bought for $10 at Home Depot.
Step 2: Merge Viewer Lens and Film Canister
Thus, you need to drill a hole in the bottom of the canister. The drill bit you will need depends on the thread size of the security viewer. The security viewer should fit snugly inside the hole. If you're viewer came with a screw that allows for different door widths, it would be good to screw that on - just for extra insurance that the viewer will not fall off the canister.
Step 3: Attach "lens" to Flip Mino
To attach the "lens" to the Flip Mino, you will need those rubber bands that you got. The rubber bands will go from bottom of the film canister, where there is space between the canister and the security viewer, to the Flip Mino. The rubber bands fit snugly when they are at the bottom of the Flip Mino's display. You could use one rubber band instead of two, but having two just gave me extra insurance that the "lens" wouldn't fall off.
Step 4: Using Your New "lens"
Place the lens on the Flip Mino as described in the previous step. Turn on the camera, and start recording. You may find that you are getting more film canister than the actual fish eye. To fix this I have found you can zoom in a bit; though that comes with a con - you lose a bit of quality. Though what can you expect for something that cost $10.