sort of visio alternative

I've just discovered gliffy , an beautiful example of Ajax powered application which can be freely used to draw diagrams. For a entry-level user of Visio (like me) this can be very useful.

I don't need all the power and fancy stuff of Visio, I just need to sometimes draw diagrams representing different things.

You can export to SVG, PNG or GIF, you can even publish on line the drawed diagrams.

Check it out, I really like it.