[edit: Even brilliant minds like myself can occasionally be wrong, as Fire In the Hole points out.  This thing is working at work but not at home!!  Strange.]

Many of you out there have probably heard of the wonderful Foxylicious, which syncs up your delicious bookmarks to a folder in your Firefox bookmarks. Unfortunately, the plugin doesn't seem to work with the new version of Firefox, despite the web page seemingly insisting that it does! The last time the plugin was authored was about 2 months ago, so maybe a fix is in the works.

Or, this might be a good excuse to try authoring a Mozilla plugin...