Bring any old disused electronic item you may have, be it a printer, scanner, hardrive (the more physical the item the better and stear clear of monitors). We'll have tools on hand to disassemble things (or bring your item pre disassembled). Then talk to the "experts" on hand about what the inside bits and bobs can be used for.
(add any item you plan on bringing here that way peopel can bone up on the appropriate knoweldge area)
-Pre Dissasembled bubble jet printer (@oomlout) (a stepper motor and DC motor, along with an optical encoder strip which might be interesting) (I'll have a few L293's (dual h-bridge chips) and ULN2803 (8 transistors in a DIP package) with me and will try to get them running (I'll have a few extras which I can part with at cost if you bring a stepper motor or motor which needs one(£1-£2)
(any questions add them here)