How can I fix my Speedo/Cigarette lighter in my S Reg Corsa 1.0?

I dropped a screw in my cigarette lighter and it blew the fuse... and when that fuse went, my speedo stopped working. everything else is fine (except my powersteering, thats a bit dodgy at times) I can't understand which fuse it is. Are the lighter and the speedo connected to one fuse? (this seems likely because I blew a fuse a while ago and 3 separate things stopped working.
Anyone have a clue which fuse it is?