At my work i'm using a windows 7 laptop and was really enjoying the automatic resizing app. What it does? It automatically resizes windows in 3 different flavours:
If you drag it to either the left or the right your window will resize to exactly half of the screen width on either your left of right half. If you drag it to the top, it will automatically full screen your window. Cool huh?
Drag it away from the snapped position and you get your old size back, brilliant! I use it a lot since I have this big widescreen and one window will easily fit half the screen. But since I'm lazy and don't like resizing I used to just full screen everything. Now I can arrange it all neat and tidy next to each other with a simple motion, yay.
Now comes the good part, being a sort of lazy person at home to I would like to use it there as well, but I have windows vista... Thankfully there is a God and someone was inspired (this word actually means "given in by the spirit", from "in spiritus" and that sort of thing) to write a program to exactly that for windows vista and xp! double yay!
It's called Aero Snap and it works just like the win 7 snap feature. Simple, clever and powerfull as the developers put it :)
Visit the website here; http://www.aerosnap.de/index_eng.htm