http://www.sportsmenscr.com/
if you are going in May, you better try booking now.
it is very, very popular and has plenty of freelance little darlings.
lately, there have been reports of 'Ciencitis' but I'm sure you can bargain.
I like to politely remind them upon requests of a Cien that there are also MP's within walking distance with prices ranging from about 10 bucks per half hour to about 40 bucks an hour.
hotel m is also nice, but pricier.
http://www.hotelmcostarica.com/
and then you always have your stand by Hotel Presidente, Hotel Del Rey, etc....
and, for the truly adventurous, the Cardboard Inn run by a fellow member out of the Pits of Jax.
however, I would reserve soon for a May trip. (with the exception of the Cardboard Inn, the owner is in the middle of an ambitious expansion plan and always has plenty of rooms...ask him about the suite under the overhang in front of the former Nasty Rasta store)
