Oooh my old home area
Well, if you're considering Ely from Cambridge you may as well pop over to Wicken Fen if you want a bit of nature/wildlife. Wicken also has some great open horizons for sunset/sunrise shots if the sky is looking promising.
There's some great little quaint village pubs, maltings, etc - pretty much every place you drive through will have something. Get off the main roads a bit and try the farm tracks (you may want an OS map and a navigator) if you really want to find some backwaters. Upware may be worth a look; canal boats, open water, nice pub, reeds; typical fen landscape with the added attraction of beer.
Stretham steam engine may be worth a look. Not been there for 20 years though so can't guarantee anything.
Cambridge itself has, obviously, the colleges, and punting (as already mentioned) is a good way of getting around the backs. There's usually some good candid opportunities through Christs Pieces and Parkers Piece (the two big green areas in the centre of town), and walking down to The Anchor pub by the punting station there's some great architecture.
For more industrial type photos, there's some shots from and around the station you can play with.
I'll put my thinking cap on and try and add some more later.