I suggest renting a villa in the southern, less traveled part of the peninsula (check out http://www.phuket.net/rentals/villa-1215.htm for some seriously nice places to stay). The ocean was absolutely pristine, with white sand beaches as far as you can see. And, if salt water's not your thing, most hotels and villas have a pool. We hired a cook who prepared authentic Thai food daily and indulged in a full course of relation. A highlight, of course, is receiving the $10/hour masseuse that comes to visit you in the hotel.
For a bit of a tourist attraction, you can ride an elephant (only recommended if you happen to be traveling with families). Be sure to visit one of the more animal friendly places (it's pretty easy to tell the difference)!
And, if you're in need of an urban fix, check out Pantong. The nightclubs will mix a stiff, fruity cocktail.
The sun is strong, so be sure to pack plenty of sunblock. But, given the weather around here lately, I'd trade having to clog my pores with sunblock over wearing rain boots in a heart beat. So, here's to hoping that we get to wear sunblock around here soon!