Hacking WTF's a thumb strap?

[phoood]

I've googled information and I've seen pictures, but they look like regular strap thingys.

Someone please upload a picture of it in action.

Also, is this any good? ( http://www.amazon.com/gp/product/B0007XS25...2106897-3194410 ).
I have Metroid: Prime Hunters and playing with a stylus sucks. So the above might be an alternative.

Yes, it goes on your index/etc. finger, not the thumb.. although..
And don't order too many, save one for me =D.

Your opinion please?