Here is a pretty decent game to kill some time.  Basically it is a Tetris like game with a few twists  thrown to make it interesting.

Ka-Glom, a high-pressure game of falling blocks, is now available for Windows Mobile. In this popular mobile game, you combine the explosive Ka-Glom jelly and connect Ka-Gloms to start an explosive reaction that blows away connecting blocks of one color. As you build huge chain-reaction explosions, your Ka-Glom factor increases and your bonus points multiply. Play in Survival mode for a classic puzzle experience, or try some deep thinking with the Puzzle mode.
Features

• Three play modes so you can vary the game experience.
• Hidden modes that you can unlock as your skill builds.
• An easy and quick tutorial so you can get on with the fun.

You can get it here