People who like and hate the aerosnap feature on Windows 7 are about 50/50. I happen to be in the like group. Unfortunately, since I am still stuck in the Stone Age with XP and Vista laptops, I have been looking for a utility that would replicate this function.
I used to use a program call AeroSnap, but it was a bit buggy and the author of the program has long since stop updating it. You can still find it on CNET (here). If you follow the link to the publisher’s home page, you will see that even the website is gone.
Very recently, I find a new program that close to replicate the aerosnap function – called WinSplit Revolution. It does a full set of window managing feature – though I just use the aerosnap function. You can define hotkeys to snap your windows, and you can snap them more than just the left, right, top, and bottom. However, as far as I can tell, it doesn’t allow you to do it with the mouse. (I.e., move the window to the right edge of the screen to have it snap to the right side.)
So, not an optimal solution – but second best is good enough for me.
You can read about and download WinSplit Revolution (here). It is a freeware.