In reply to another_mark: Yeah, I'd say trekking down to northumberland's your best bet, although i did read about some big limestone blocks a little way west of edinburgh, but that's probably just as far? Try Bowden Doors (And Back Bowden), Kyloe (kyloe in & out of the woods), and Dovehole Boulders (although i hear that Dovehole is like climbing up a beach) for some places nearer the borders, but there's stuff all the way down to Newcastle and beyond it seems. I'd be happy to climb with you some time if you're looking for someone to climb with? As I live right next to Bowden Doors.
I can appreciate however that it's quite a trek to get to those crags, but it's worth it! I've met people from edinburgh, and even from sheffield, up at bowden!