Autodesk Project Draw

Project Draw is a new feature-rich web-based vector drawing application built by the Labs team. Use it to create simple floor plans, electronic-circuit diagrams, network diagrams, user interface mock-ups, and more. Save your work in a variety of formats on our server or yours. No plug-ins or downloads required - if you have a JavaScript-enabled Internet Explorer or Firefox browser, you’re good to go. If you've registered with Autodesk Labs, logon and try Project Draw out now!
Features include:
  • Predefined shapes - drag and drop our vector shapes to create custom diagrams.
  • Save your diagram in editable formats.
  • Export your diagrams in a variety of formats, including PDF, JPG, PNG, and SVG.
  • Cross-browser compatible - create a diagram in IE, open it in Firefox, or vice-versa.
  • Handles - drag the shape handle to stretch dimensions.
  • Linear, curved, and orthogonal connectors available.
  • Imperial and metric page sizes available.
  • Text tools, gradients, shadows, zoom, dimensions, snap-to-grid, and more - we’re adding new features all the time based on your feedback.
http://labs.autodesk.com/technologies/draw/

Project Draw:
http://draw.labs.autodesk.com