Looe itself has a working harbour and fish market. You can go mackerel fishing in the bay for 2 hours, that's pleasant on a nice day. You'll see people fishing for crabs with a line over the over the harbour wall. Close to Looe there is a monkey sanctuary - another enjoyable memory from years ago -
http://www.chycor.co.uk/monkey-sanctuary/index.htmDon't bother going to Trago Mills which is an over-hyped shopping trip
Eden project suffers from traffic problems. Going anywhere from Looe, but especially west, takes twice as long as it should. Definitely skip Lands End (from Looe) - would take way too long for not much interest.
There is a coastal walk all the way around Cornwall. The walk from East Looe to Polperro is reasonably easy and quite spectacular, and Polperro is a very quaint place (yet another harbour...). See
http://www.jbutler.org.uk/e2e/sccp/w13/index.shtmlLooe itself is cute but is mainly tacky tourist souvenir shops but there are a couple of nice pubs (avoid those on the front) and the pasty shop about half way down the high street has a wide range of fillings.
If you'd been there a few weeks later (17 August) you could have seen the Red Arrows over Fowey harbour - saw them once and it was stunning. But you are too early for that. (2004 pics here
http://www.raf.mod.uk/reds/archive04aug.html)
Can't think of much else now but will post again if I do...