Nik talks a lot of sense about technical interviews. As a purely anecdotal aside, I’m pretty sure that the interviews where I’ve been asked the kinds of questions that he’s talking about have lead to some of the jobs that I have least enjoyed.
And, as Nik mentions, this is all in the context of Guardian Unlimited looking for a lot of new employees (I can’t help wondering how permanent that URL is). Having worked at GU a couple of times, I’d recommend working there to anyone. It’s certainly one of the best places I’ve ever worked.