You can--as an American, you just need to enter and exit Cuba through another country (Mexico, Canada, or somewhere else). If you go, be careful--Cuba charges an extra 10% to exchange American money.
I was there around the same time as you! Stayed at the Melia Las Americas becaus of their free golf deal. The golf course is a little run-down, but the ocean is in view for many of the holes, and I still hit every club in the bag, so it's good enough!!!
Everyone else's comments are spot-on as well. The Cuban people are delightful! This was my second trip to Varedero, and while I didn't exactly go for the food, some of the seafood you have there is delicious. I have to admit, I have a soft-spot for their cigars as well...............
. The next time I go, I think I'd like to explore the country-side a little bit.
I'll see if I can get some pics posted too! One of the more interesting things I did was to rent a scooter ($25 for 24 hours) and go into the town of Varedero. interesting shopping and a little culture as well--although nothing like heading to "La Habana".
Glad you had a great time! For me, the decision between Cuba and Dominican is Cuba all the way. some of the higher-end Dominican resorts are nicer, but at that price point you should start looking at at other middle-end destinations in the Carribbean Jamaica, Bahamas, etc). On a side note, I met many great Domicans, but as a whole, they are more agressive towards the tourists than then Cubans.
Next stop, Turks and Caicos for 8 days starting on April 19th! Anyone been?