Imagination Cubed is an amazing, free online communication tool developed by General Electric (GE) as part of its global marketing campaign, Imagination at Work.

For many people, the easiest way to explain a complex idea to someone else is to pick up a pad and pencil and start sketching it out in front of them. This is, of course, especially true for those of us whose visual sense is more acute than our auditory sense.

But this has never been possible when you're communicating with someone online. Imagination Cubed brings a whole new dimension to online idea-generation.

The stunningly simple and minimalist HTML/Flash-based interface disguises what has to be some extremely sophisticated web and communications applications. The tool can be used as easily (possibly more easily) by young kids as by grown-up online co-workers.

You start out by drawing whatever you wish on the clean white interface, using your mouse to guide the pen. You can configure the pen to draw in different line weights and it's remarkably responsive and accurate in following your mouse's movements. You can also draw straight lines and there's an eraser function.

The Tools button at the top of the screen allows you to draw a selection of shapes as well as to 'stamp' a wide range of emoticon-type images into your sketch.

Where the tool really comes into its own is that it allows you to invite up to three other people, via email or Instant Messaging (AOL IM only), to interact simultaneously with the sketch.

Each participant is given their own named pen, in a different colour, and each can add or edit the sketch in real-time, through drawing and/or through the customized chat interface.

Once you have all completed your sketch, a click on the Reply button will do exactly that - replay precisely all the sketch inputs everyone made, in the order they made them.

The possibilities are endless.