To have a DNA test?

[FlamedToACrisp]

Is it worth doing a DNA test for family history purposes? Is it accurate enough to be worth bothering?

I already know who my family are, but would like to meet other relatives/confirm relationships.

I think the idea is interesting, but it seems so overpriced (and the £20 'extra' charge for postage annoys me!) I just don't want to spend out £100 unless I'm sure the results will be accurate. But I'm not worried about OMG-my-Dad's-not-really-my-Dad results, as my parents are dead. I'd like to get in touch with my American relatives.

I’ve been doing my family tree via Ancestry for years now and this is what I’ve asked for from Santa this year.