Or keep an empty plain text file on your desktop and set it as a stationery pad from the Get Info window. All you need to do is double-click it (or command-arrowdown if you prefer).

What's still pissing me off about OS X stationery pad is that it automatically creates a copy of the pad. In previous OSes, stationery pad creates an unsaved copy of the pad that you can later decides to save into another folder with another name or simply discard without having to go to the Finder and rename/move the file around.

How about this, create a new file from clipboard:

pbpaste > ~/Desktop/untitled.txt; open -e ~/Desktop/untitled.txt

This will overwrite exsiting file that bears the same name though. But you can either combine it with OnMyCommand from abracode.com or with applescript.