Hi Ollie,
I had a bit of a play with HDR a few years ago and quite enjoyed the challenge of it.
The photos look great when its done well, and used appropriately - and can look awful when its not. One of the best examples of HDR I've ever seen is Trey Ratcliffs work (
www.stuckincustoms.com ) and I believe he does quite a few tutorials too, so its definitely worth checking out his site.
It's definitely not an easy technique to get to grips with, but it's worth it when you do.
James