I use the "grid" option of CompizConfig Settings Manager. "Grid" is developed as an extra plugin, so you have to install compiz-fusion-plugins-extra package (I couldn't see this in "software center", so did it through synaptic).
Once you have the plugins installed, in CCSM, go to "Window Managment", then select "Grid". I modify my "put left" to be CTRL + SHIFT + left arrow (and do likewise for "put right", "put top", and "put bottom"). I map CTRL + SHIFT + enter to be "put center".
I am not sure about W7, but the GREAT thing about GRID is that if you hit it once, it will go to half the screen. A second time goes to 1/3 of the screen. A third time has it take up 2/3 of the screen. Then, a fourth has it back to half. So, you can set up documents side by side that need 1/3 or 2/3 of the screen as well as equally sharing 1/2 of the screen.
A MUST plugin for me in Linux! And it works great!
Unity will be coming with a "snap feature" included, but I like the keyboard to do this setup for me! CCSM GRID it is!