Utilla and Roatan
If you are scuba divers (or want to become one) Utilla and Roatan Islands are worth a visit. I have friends who have dived on Roatan and loved it. I went to Utilla to dive for 4 days and it was pretty good (but I'm spoiled by having dived in some of the best places in the world). Utilla is loaded with dive shops offering inexpensive training courses.
To get there you take the ferry from La Ceiba to either island. Unfortunately it is passenger only. Getting your bike to Roatan is a major hassle involving cargo boats. Utilla is to small to be worth it. You can park in a secure lot at the ferry dock (I chained mine to an antenna tower).
Panama City, Panama