OK the name is cheezy, but my goal was to write this thing before #24 ends.
It's really simple. All you need to do is drag the following link to your bookmark bar (this has been tested in Firefox ONLY)
Rot13 Bookmark
Once the bookmarklet is on your bookmark bar click on it to post a rot13 tweet. To un "encrypt" a tweek, select the rot13 text and click the bookmarklet.
Pretty simple!
To discuss this please go here
Kudos to JS from Hell for the rot13 function