As my one-way commute is 43 km, I usually do a short ride, either to a port in the river (upstream from Buenos Aires), take a boat and then ride to work, riding all the way back to home.

Also I had taken the train (with a 10 km commute to the nearest train station) or meeting a friend who has a truck and loading the bike in it.

The best one by far is the boat, I go from Tigre to downtown Buenos Aires with no sight of cars at all, only sailboats and cargo ships :-)
http://maps.google.com/maps?f=q&sour...79529&t=m&z=11

Regards
Javier