One thing you
must do if you're in San An bay is catch a sunset at Kumharas.
You could also leg it accross the bay and go scuba diving for the day- can't remember the cost, but I've still got a photo of me under the water at a depth of about 20 metres
Bar M, Itaca and Orange Corner are on the way to San An Town.
You could explore the local beaches.
You could get a boat accross the bay, have a meal at my favourite place to eat (El Rincon de Pepe) and then go and catch a sunset at Cafe del Mar, Cafe Mambo, Coastline, Savannah's or Kanya.
Whatever you choose to do I'm sure you'll have a great time!
Oh, and if you do hire a vehicle, you could go to the hippy market at Es Cana or San Carles, or catch one of the nights at Las Dalias which are not only cheaper, but better than the big clubs IMHO.