Making use of Google App Engine, with some help from Euan, I made a little app that lets you store a list of your PubMed publications.
It's not the first to do this (see the Medline Publications app on Facebook), nor is it finished (there's a bug that stops it working in Safari, but I'm locked out of updating it because of App Engine's 'googlemail.com' bug, which is also why the app at a temporary subdomain on someone else's account [fixed!]), but it does the basics.
Basically, sign in, run a PubMed search and click to select the papers that are yours. Refresh the page and they should be stored.
Update: now with export options: Atom, JSON, (basic) RDF.
TODO: OpenSocial widget.