There is a canal in Panama!
We did the trip by bus in 9 days with stopovers in San Jose, David, and Cd. Panama, with a day trip to Boquete. Worth doing, but a lot of bus time. If you don´t want to sleep on the bus (tica Bus), there are other options. Tracopa in SJ (ask the taxista for the new station as they have moved recently) has a 0730 bus direct to David. The bus station in David (yes, one bus station, contrary to most of Central America) has frequent buses to the capital. David doesn´t have much of interest for tourists, but it´s a decent, clean, modern privincial capital with banks, etc., and is a short bus ride from Boquete in the mountains. In Panama we also saw the ruins at Panama Viejo, the partially restored Casco Viejo (old town), and the Amador Causeway (which puts Mission Bay in San Diego to shame!). For a quick but adequate look at the canal, go to Miraflores Locks. It´s run like a US-type natonal park with movie, dislays, observation decks, etc.
Didnt have time to take the train across the country or make other stops, but found Panama to be very interesting.