Zeta Flow

http://fantasticcontraption.com/
I LOVE it! It has officially stolen my life.

Played that one for a while, took up quite a bit of time for me as well.
I still occasionally go back to see if I can try levels differently.

You might like this one as well ... http://magic.pen.fizzlebot.com/magic-pen.swf

Great, now I'm addicted!

I also played it for a while but got bored quicklly. Personaly, I dont think it is as good as Zeta Flow (great game MD).
It almost took up an hour of my time (sorry for not getting around latly I've been busy trying to make design concepts for my zeta flow level series).

I lost a bit of time on that as well but have managed to ween myself off now. Still prefer Zeta Flow though

Yeah.

Zetaflow is a great site. Even though MD doesn't get around much for updateing, the main users still make new levels to expand the site.