A common problem for every widget developer is getting data from the page to the server. The main obstacle is the cross-domain support or the lack there of. This is not as much as a problem when you're sending small amounts of the data - you can load scripts from other domains sending the data through the GET request. A completely different story is the sending of lots of data, where you would normally need a POST request. Until now there were just a few possible solutions - use a Flash cross-domain bridge and build your own browser extension being the most prominent.

Now on you can easily use a new technique, first presented by Kris Zyp who wrote a dojo implementation for it. I was hoping that somebody would port this to other libraries but since nobody did I decided to do it myself. And a week later you can download the jQuery plugin.