to stop broken/misleading links like this happening on Twitter:
twitipedia turns links like http://en.wikipedia.org/wiki/The_Muppets_(film)
into links like http://en.wikipedia.org/wiki/The_Muppets_%28film%29
Why? Because when pasting the addresses of Wikipedia articles with parentheses (round brackets) in them to Twitter, the links come out broken (because Twitter* interprets the opening parenthesis as the end of the address, then shortens that broken link for use in your tweet).
What? twitipedia simply replaces any parentheses (round brackets) with alternative characters and then gives the user the opportunity to copy the Twitter-safe address to the clipboard.
How? Drag it to your bookmarks toolbar to install; click the button to use (when on a Wikipedia article page). To remove it, just remove the bookmark.
Who? This is matatk's first bookmarklet (and github foray).
Note: tested on Safari, Firefox and Chrome; not on Internet Explorer.
* at least the official Mac client