The Gorillapod SLR-ZOOM is designed with the serious photographer in mind. It attaches to SLRs (with zoom lenses!), video cameras and professional tripod heads, and it can support up to 6.6 lbs (3 kg)!
Some people use them for attaching flashes to stuff too.

I got one free with a magazine subscription.

I have an SLR zoom version. It's fine for what I want. The SLR zoom has no quick release top like the SLR and the mini one, so you'll need a quick release mount otherwise it's too cumbersome. I bought a cullman quick shoe off ebay for about a fiver. It's great, if I want a quick steady shot just whip the gorillapod out and slide the camera on.
Shop around if you want one though, a lot of places are still retailing them at the RRP of around £50. I got one for £32 about 3 weeks ago off an on-line retailer, www.lowpricememory.co.uk