TetriCycle is Tetris projected onto a cylindrical surface. Rotate the cylinder left/right such that the descending piece falls into place.
TetriCycle is freeware, can be distributed freely and should never be charged for.
v0.4b
4th Release: 7/19/10
Shadow option -- see where the current piece will drop.
Preview option -- see what the next piece will be.
Multiplayer looks better. Each playfield is drawn from the same perspective, but with a shifted viewport.