I [posted yesterday about Moom](http://brooksreview.net/2011/06/moom/) and how it makes use of the damned green button again. Cody Fink has a great review of yet another app in this category called Flexiglass.
What piques my interest about this app is the ‘real zoom’ option that makes the green button just throw the window to fullscreen (I can hear former Windows users rejoicing now). It also has some multi-touch gesture support, which looks neat.
I don’t use these apps enough to try and switch from Moom now, but it does look pretty nice. ((Bonus points for having a better name than Moom too, though that isn’t that hard.))