Disobey Gravity

Cams are great. They fit in parallel or even slightly flared cracks in the rock into which you'd never get a nut safely, and if you fall on them it makes them grip the rock harder. Also, they're very aesthetically pleasing devices[1]. Ignoring for a moment micro-cams which you'll probably only need if climbing in the E-grades, there are several different options, with either single or double-stem, made by Wild Country, DMM, Metolius, or Black Diamond.

On my first trad climbing trip, I got to try a range of different cams from our instructor's rack, and since then I've bought some Dragon Cams, and have used them on limestone, rhyolite, and quartzite. I think they're really good - they have a pretty good range of widths for each cam, and I find the thumb-trigger design much nicer to use than the loops you get on the C4 Camelots. They're a bit stiffer to operate than some other cams, but that means they feel a bit more secure in the rock. The extendable sling is a real plus on meandering mountain routes, too - quite often I don't need to use a quickdraw on my Dragons.

In the end, the best way to decide what cams you like is to play with different ones and see what they feel like, but I'd definitely recommend giving the Dragons a go. I'm very pleased with mine and they are sooo shiny!

[1] I may have been known to happily sit playing with the mechanism on my cams...