Foofurple's HTML5 Simple Fundraising Thermometer
A simple HTML5 Canvas / pure javascript app that lets the user create a fundraising thermometer image.
The nice thing about this is that it isn't a widget or plugin that needs to be installed, it just generates a .png image which can be used anywhere.
PUBLIC DOMAIN because it's a completely obvious thing to do and in a sane world no-one would think to apply the concept of intellectual property to something like this :)
See it in action at foofurple.com/thermometer/