During my recent (06/2006) work at AITIA International, Inc., I managed to create the Online Image Map Editor that is available at : http://www.maschek.hu/imagemap.
With the help of the editor you can easily draw ALL the standard image map shapes (rectangle, circle, polygon), and you will have full control over the generated HTML code as well.
The editor natively uses the canvas HTML element to draw the shapes on a given image. The ExplorerCanvas library from Google is used to get the same result in browsers, that does not support the canvas element but can use VML instead. ExplorerCanvas works quite well, however it is still beta quality, and not as fast as the native canvas drawing, so expect some lags in IE. The editor is currently tested to work in FFX 1.5 and IE 6/7. Due to some problems of canvas resizing the editor can only draw rectangles in Opera 9+ browsers.
Feel free to play around with the editor: use your own images or use the built in samples, draw your areas or edit the HTML code, save the result to your clipboard.