If you want more than one scratch buffer--which happens to me once in a while--you can just create a new buffer with any name, and it will also do. New buffers are in a different mode by default, but you can set it up to work exactly the same way as scratch if you want.
Just a fun alternative to this trick for the Emacs users around here :).
I keep it in textmate, been thinking about moving it to vim but I quite like having it in its own space.
edit: misread your comment, thought you were comparing :new and :Scratch (linked above), not emacs' scratch. Not sure about that one, but again, the 'reopen scratch -> find leftover contents' functionality is a neat thing.