For those of a more artistic bent, there are numerous art galleries, and St Ives is especially noted for the number of galleries proliferating to serve the tourist.  Newlyn also has a noted history for painted art.
For the visual arts, the Hall for Cornwall in Truro puts on some superb productions http://www.hallforcornwall.co.uk/, but a not-to-be-missed experience is taking a picnic (and wine!) down to the Minack theatre to share with friends before a performance.  The magic as daylight fades and the stage lighting takes over during the performance is unbelievable. http://www.minack.com/

Entertainments
It would be impossible to give a complete list of all entertainments in West Cornwall.  There are many brochures which attempt to do so, and none manage to provide a comprehensive list. One great problem is that what one person considers an entertainment would bore another to death!

Cornwall has a multitude of ‘family’ entertainments, varying from theme-park type places, through to swimming pools, and of course, the beach.  For an ‘eco friendly’ day a trip to Eden

For those with an interest in gliding http://members.aol.com/cornglide/page1.htm is the web site of the Cornish Gliding and Flying Club.  This is the only public access gliding club in Cornwall (the only other club being the one at Culdrose Naval Station, near Helston).  The club runs two two-seater gliders, and two single seaters.  Launching is normally with a Pawnee tug plane, but winching is available at times it will not affect other flying at the airfield.
(I have recently been told that the club has gone into liquidation, but have not been able to confirm this.  The website still exists but appears to be out of date.)

(http://www.edenproject.com/) takes some beating, but listen carefully to the local radio for news about how to avoid the traffic jams!  (103.9FM or www.bbc.co.uk/cornwall)  Eden has problems of access caused by its own success.

For the inshore fisherman (or woman) some of the best places are of the rocky shore to the east of the lizard peninsula (dependant on weather conditions).  Many of the local fishermen will also be prepared to take visitors out to the inshore fishing areas for a chance of the deeper water fish.  One that has been recommended to me is http://www.cornishfishing.co.uk/index_files/Page670.htm  but the trip I had booked was cancelled because of rough weather!

Nothing tastes better than a fish eaten within hours of being caught, although the taste may spoil you for the usual supermarket variety.  A close second best can be had from the fresh fish shops around Newlyn (and recently opened in the arcade in Redruth)