Random ideas
Things we could do but don't have the detail or support to rise to the level of grants proposals
Photography based
ROV
Buy and constuct an ROV (http://www.robotshop.com/gorobotics/the-news/hobbyist/build-your-own-underwater-rov-for-250 $250 version here although there are better options). Use to get photos of marine life and wrecks.
Photograph every coin
Work with museums and other collections to try and get us the access needed to photograph every pre 1860 coin ever. Tokens can decided one way or another.
Source based
Old journals
Offer to digitalise and host the older journals of the likes of the Sussex Archaeological Collections which would provide wikipedians with more access to good local history sources.
Journal of citation needed
Set up an open access journal with the stated aim of publishing papers in those areas wikipedia finds it difficult to get sources for
Old newpapers
Buy a microfilm scanner and scan and OCR old local newpapers.