Independent software developer Dave Taubler has released OverSite 4.0 (http://www.taubler.com/oversite), an update to his wireframing and interaction design application for Mac OS X.
The new version adds: new widgets, the ability to colorize the page background. and the ability to colorize individual spreadsheet cells. Also, wireframe canvases can now autosize to fit components.
The registration cost for new users is US$65; existing users can upgrade for $30. OverSite is compatible with PowerPC and Intel-based Macs running Mac OS X 10.3 or later.