In reply to afx22:
I wouldn't travel to the bouldering at Coniston, it's not brilliant. In the Lakes, St Bees is fantastic (search the videos on here, there are a couple I think) but bloody miles to drive from anywhere. Carrock Fell is good with lots there and some brilliant problems scattered here and there amongst the mediocrity. Other than that, unless you're into the esoteric world of mountain bouldering, I don't rate the Lakes too much as bouldering destination. You can often find yourself walking for miles up a steep, wet, grassy hill looking for what turns out eventually to be a steep, wet, grassy lump of rock. If you like training on a cellar board, and want to go on a really massive one with no friction, then head to the Bowderstone. I think the fact that I can only do one problem there spoils it for me, but it's not really what bouldering's about for me - it's indoor climbing outdoors. With disabled access, a gravel landing and an audience of obese tourists.
Personally, I think that bouldering on limestone is about as fun as surfing on sewage. There's plenty of that around the South Lakes (limestone, that is) and it's god awful.
I don't know it yet, but Northumberland looks awesome. I'm going to explore the sunny bits this winter. For bouldering, sandstone (including grit of course) is where it's at. Mountain rock (rhyolite) can be OK, but it's usually a matter of pulling very hard on horrible sharp holds (although the Langdale boulders are an exception, lovely and grippy, almost grit like) rather than cool moves using friction.