AppleScript to snap windows to the left à la Windows 7 Aero Snap

gistfile1.scpt

-- get Dock height
tell application "System Events" to tell process "Dock"
	set dock_dimensions to size in list 1
	set dock_height to item 2 of dock_dimensions
end tell
-- get the new width and height for the window
tell application "Finder"
	set desktop_dimensions to bounds of window of desktop
	set new_width to (item 3 of desktop_dimensions) / 2
	set new_height to (item 4 of desktop_dimensions) - dock_height
end tell
-- get active window
tell application "System Events"
	set frontApp to name of first application process whose frontmost is true
end tell
-- resize window
tell application frontApp
	activate
	set bounds of window 1 to {0, 0, new_width, new_height}
end tell