So, my weekend is filled with doing a bunch of wireframes for a few projects.  What better way to test out Mockingbird, a web based wireframe application I’ve been meaning to test-drive.  Mockingbird is perfect for doing wireframes on the go, with all the goodies you’d expect in such an app but many you might not - sharing, linking of pages, preview.  A big plus is that it uses Cappuccino rather than Flash.  My biggest issue when working was that Undo and Redo weren’t linked to hotkeys like all the other Edit functions (it should be in the Edit menu, which is fairly standard).  This proved annoying.  Nice-to-haves would be more export options - they have PNG and PDF, but PPT/PPTX would come in handy.  Although there appears to be only two people developing and managing the product, customer service was prompt and useful (thanks Sheena Pakanati).  Great work.