A month or two ago I was toying with making a Katamari Damacy clone and produced a little demo, "Catamary".

It's not much and I haven't had time to work on it since but for those needing badly to roll over something here it is: http://clydeshaffer.com/clydeshaffer/downloadables/catamary.rar
The controls are WASD and IJKL to imitate the double-directional controls from the playstation. Also if you press spacebar the ball pulls a complete 180 degree (or 2 * pi radian :D) turn.