Twiddla, a free whiteboarding service that doesn't require sign-ups to start using, turns any web site, photo or graphic file into a canvas for marking and discussion. Winner of this year's Technical Achievement award at the SXSW festival, Twiddla isn't the only
whiteboard service, for sure, but its ease of use and quick setup and extra features—including live conference-call-style audio chat—make it a stand-out. You can check out Twiddla's features without even launching a "guest" account by trying out its live "sandbox" mode. For web workers, design types, and anyone needing to draw out or discuss an idea, it's a worthy tool to keep bookmarked.