Via Pharyngula comes a gem of a time-waster.
Assemnbler
Assembler is a new physics based wonder where you move some depository equipment to get your precious green crate in position. For what? No matter! Physics work perfect and the feel of grabbing and moving around things is just perfect. Don’t play too much or you’ll dream of dirty green crates flying around.
It's a puzzle game with an interesting twist. An accurate (and very sensitive) physics engine. The mass of movable objects seems to correlate directly with size (i.e. they all have a uniform density) at least at the low levels I've played so far. The coefficient of friction also seems to be 1. Rotation (angular velocity) is taken into account during collisions, too. It is very easy to knock a carefully placed piece across the board. It's a lot of fun. Try it.
Later,
UPDATE: Dammit! There are only 17 levels, and the hardest took me 3 minutes. Not because I couldn't figure out a way to do it; it took me that long to finesse the objects into the positions I wanted them. Still, it was fun, and I look forward to new levels.
Later,