The Click to Tweet button in Notification Center is just crying out for a way to activate it without taking your hands off your keyboard. Over at StackExchange, user Ewwis posted the following AppleScript. Save this and launch it with, say, LaunchBar or another launcher. It displays a dialog where you can post your tweet, then, when you click on OK, displays Notification Center and sends your tweet.
display dialog "Tweet?" default answer "" buttons {"OK"} default button 1
set mytweet to text returned of result
tell application "System Events"
tell process "Notification Center"
click menu bar item 1 of menu bar 1
click button 1 of UI element 1 of row 2 of table 1 of scroll area 1 of window "window"
keystroke mytweet
keystroke "D" using {command down, shift down}
keystroke space
end tell
end tell
Mac OS X Hints
http://hints.macworld.com/article.php?story=20120819231916737