A Safari5-compatible update of an old SIMBL plugin. In its current form, takes you to Twitter.com with the tweet field autofilled with the name and URL of the page you were on when you pressed the button. This is a preview release, so improvements may be forthcoming. The SIMBL-based input manager version is also available for users of older versions of Safari.
Variously submitted by several readers (including @cglong and @splorp) and the developer.
EDIT: My mistake; it was an input manager.
