In reply to MikeSilverstone:
New Mills Torrs - Under a bridge so stays dry on one part
Parisella's Cave - Seeps and also can condense out if the temperature rises quickly so not always climbable.
Carreg Hyll-Drem - Very overhanging. Often can get something done when raining.
Raven Tor (Miller's Dale) - Often some bouldering available even when raining due to the overhanging nature of the crag.
Back Bowden Doors - Often some bouldering available under the big roofs. Be careful though as sandstone and has the potential to snap if it is damp.
Woodhouse Scar - Angel face is pretty much perma dry and good for eliminates.