DISQUS

One thing to consider with such a plugin is that there will likely be communities of users who share similar vocabularies of Tooltips and Acronyms. It would seem a shame to force each user to (re)create entries, and it would make things much easier to maintain if such lists were shared. Imagine if, rather than reading the definitions of tooltips / acronyms from a local source, the datasource was shared on the net somewhere. (This could be a simple RDF server, as an example.) Now, if anyone anywhere makes an update to the datasource, all users benefit. Of course, there would be problems with "graffiti" and poor-quality content on such a shared, open datasource, but perhaps some wikipedia-ish techniques can manage such vandalism. It also would encourage people to use the plugin, since as soon as you drop it in, your site is dramatically enhanced by the collective intelligence of the web. Hey, I might even be able to help on the server side!