Clever, but why? Notepad.exe, TextEdit.app, Gedit, nano are all already there - and do save if you want to after. TextEdit will even just let you quit and come back without saving and the draft is there. Leave the browser sometimes man!
The nicest thing with using a shortcut like the one above is that all formatting is preserved, tables especially, but also other html elements with styling (mostly). This is very handy in a lot of contexts.
Also, a quick way to get a scratch pad in Emacs is to switch to a non-existent buffer. C-x b foo RET and type away in a buffer called foo.