I've been going through the same process. My current tripod plus ball head is 4.0 lb, and that was considered light when I bought it years ago (Gitzo 120, Giotto M1002). I never take it backpacking, just local walks and sometimes dayhikes. I have a small light micro 4/3 camera.
Some useful links and data:
Sirui T-025x: 1.8 lb, 54.5 " max height, $239.
Brendan's link is very informative: http://www.pentaxforums.com/reviews/sirui-t-025x-travel-tripod-review/introduction.html
This sounds like a good choice given it's weight, price and height. Very compact.
Sirui T-005x: 2.2 lb, 54.5" max height, $137.
Same as T-025x except aluminum instead of carbon and half the price. Here's a comparison of the Mefoto Backpacker vs. Sirui T-005x:
http://www.dpreview.com/forums/post/51821471 Sounds like a good choice.
Conclusion is that Sirui T-005x wins. Weight 2.2 lb vs. the T-025x 1.7lb (manufacturer's spec, Brendan says T-025x is heavier than spec, 30 oz, pentaxforums says 1.8lb. Very compact.
Slik Compact Tripod II: 1.26 lb, max height 39", $35 at BH.
Slik Sprint Mini II Tripod, 1.75 lb, max height 43", $80. This gets some good reviews at amazon: http://amzn.to/WrSl0r
Tamrac TR406 ZipShot: 11 oz, 53" max height, $53. Seems like it's being discontinued. To me, looks flimsy from it's pictures.
Ultrapod and Ultrapod II, 1.7 oz to 4.2 oz, cheap, very low height.
Bob Gross's 18 oz Targus. I can't find this. The problem with cheap light tripods is that it can be hard to find a good one; perhaps spending time at a camera show flea market with a scale. You could spend a lot of money on cheap tripods.
"Wibble wobble wibble wobble jelly on a plate" from an amazon review of a cheap tripod.
What to do? There doesn't seem to be a lot available between the 4 oz Ultrapod and travel tripods that are nearly 2 lb. I'm tempted by the Sirius T-025X or T-005X but I'd be happier if they were closer to 1 lb.