Here's a view of Tap-Taps I saw on the way to Port-au-Prince. One started out as a van, one started out as a truck, both are old and capable of some serious carpooling. The truck taptaps can carry 20 people; the vans might be limited to more like 16. At least one person has taken Tap-Taps as a symbol of how desperately bad things are in Haiti, but I kind of love them. They're so cheap and easy to use, they run frequently, and if you don't mind other people's company they aren't uncomfortable either, except on the bumpiest roads. Some have kind of sharp bits that will bang you in the back or the head a little if the vehicle goes over big bumps and you're sitting in the wrong spot.

Below is a view out the back of a Tap-Tap, where you can see several of the passengers.