Eclipse doesn't do that today and I don't know of a plug-in that adds that feature (with so many out there, there may well be one). I don't think it would be particularly difficult if you want to give it a try (add a part listener, add a resource listener, record the open / closes, etc). I would expect that it isn't really much different than the n-last open editors under the File menu.
Not a bad exercise for learning plug-ins. Mind if I borrow it?
-- Dan
Co-author of <a href="http://www.jdg2e.com" target="_blank" rel="nofollow">The Java Developer's Guide to Eclipse</a>, 2nd Edition<br />(Yahoo group <a href="http://groups.yahoo.com/group/JDG2E/" target="_blank" rel="nofollow">JDG2E</a>)