A colleague recently sent me a link for a wireframing web application called iPlotz. It appears to be a flex application in beta, and if I’m not mistaken perhaps using a variation of the Edding Black or Flekscribble themes featured on ScaleNine. Only started playing around with it, but it looks like it has potential as an online collaboration tool. Check it out for yourself at iplotz.com.
iPlotz: wireframing, mockups, and prototyping...
[...] I found this review of Balsamiq was also helpful. Coincidentally I reviewed iPlotz a while back here [...]
The makers of iPlotz later informed me that they did not use a canned theme but rather created their own.