Ambiguous autofill widget

Often you want receive more information, with your autofill widget POST data. Currently all you get is a string, optional with comma separated values.
What yo really want to send along in a POST, is at least a unique ID, such as the node ID, or user ID.
For that you need a better interface, IMO. Comma separated values in a single textarea is just fine for Tagging, but anything beyond that requires an interface that allows you to simply add/remove or change what you have found.
This mock-up is a proposal for that. I designed it for Clipper, which wants to find parent nodes.
It downgrades fine (see the bottom set, for how non-JS versions will behave.
Once you check an item, it will be placed in the fieldset ‘chosen’. The non-JS will place theme there after another ‘preview’ or search is POSTed.
Same, but vice-versa when you uncheck an item in the ‘chosen’ list.
Once you start typing in the textfield, the fieldset will show up, with a throbber and, once found, a set of options. Each option contains a checkbox. The non-JS will behave the same, only the user has to press search to perform the update of the fieldset.
The lists with found and checked can contain metadata in a tabular form, such as the posted date and the author. Each listed item could be a link to the object (node) too, though that is dangerous because it will make users browse away and thus loose the current post info.
And now the code …. :)
