No worries, yeah they've got an imposing amount of stuff in their catalogues.

Like I think I wrote earlier, the inner tubes work but they don't have a lot of elasticity to them, they're very good if you need a band that's really wide and that you can slip over onto whatever. Not so good if you've got to stretch them a lot.

And of course, there are a lot of different sized inner tubes. For what they cost, I'd probably just buy one to fit a "beach cruiser" type tire, you'll have "Ranger Bands" coming out of your ears.

Avoid the thorn resistant type, they're even less elastic and they're only thicker on the top portion which makes them stretch out kinda weird. I like nice, even stretching...;^)

In a similar vein, if you ever need a quick temporary clamp while gluing something up, try wrapping some surgical tubing around it. That stuff stretches for days and it's cheap and reusable. Also makes a handy flexible straw out in the field.