I used a tripod, just too hard to explain how to use my camera, adjust zoom, select the auto-focus zone and how I want the shot composed--and then expect them to get us all smiling with eyes open to people--particularly in Hong Kong!
My tripod went everywhere with me--often unused, but indispensible when I need it.
, on Flickr
You have a couple of options--learn to use the auto timer on your camera--almost all have one these days. Usually there's a wall, post, something you can set the camera on. Or, you can just zoom out extra wide on the shot so the "photographer" you find can't help but include everyone/everything in the shot, then just manually go back and crop it in Photoshop after the fact.
There are a number of durable, light weight tripods out there these days. I recommend the carbon fiber ones if you can afford it as they are by far the best combination of light weight and sturdiness. Then, don't skimp on the tripod head. Also lots of options, I think that the 'pistol grips' are fantastic for amatures as they're easy to use and the better ones work quite well--they just have the down side of adding bulk and length.
Finally, consider a "Gorilla Pod"--the flexiball 'ball leg' tripods. You can wrap the legs around posts, trees, rails, whatever and they make them large enough to support up to 20 lbs, so even if you shoot a DSLR with a fairly large lens it could work for you.