Hey,
When I first started writing the maps doodle, I thought that an idea like that must already exist. However, googling in that limited time did not really yield any useful results, and so I thought of writing it myself.
Today, when I was analyzing me FeedJIT table, I found that one of the visitors had visited my page using this search. Out of curiosity, I tried the search again, and that is when the second search result turned out to be a site that did something similar, but on Google Maps. The site, called QuikMaps, seemed to have good usability, and the JavaScript in it also well written.
With features like drag and drop signs, the site was an advanced version of the 24 hour that I had put in. A little more dissection showed me the simple tricks that achieved the doodling capability.
The JavaScript in the site was just a simple wrapper over the Google Maps API, using the map overlays extensively. A simple line drawn over the map surface is converted to the to the google maps PolyLines, as specified in the maps API. The images were also placed similarly. This data is saved at the server under a temporary user, and can be shared, printed, etc.
Speaking about the polylines capability in Google Maps, they are effectively placed as HTML 4 SVG tags on the map. This was the only difference from my design, where I used a canvas to overlay the polylines. A comparison between SVG and canvas is here and here. Apparently, I did not notice any difference in performance with both approaches though.
To conclude, as I have found a service that allows doodling on maps already, I may not continue development of the Maps Doodle. I think I would now start hacking into other stuff !!
