Yahoo quietly released the del.icio.us Bookmarks Firefox extension the other day, which does something I’ve been wanting del.icio.us to do for a very long time, namely fully integrate with Firefox bookmarks.

Like a lot of people, I gave up long ago on using bookmarks to keep track of interesting sites (del.icio.us fills that role quite nicely for me now). Still, the process of bookmarking something in del.icio.us had always been a bit tedious. The old del.icio.us extension helped a little (it would prefill the Notes field with whatever text was currently selected), but it was still missing some pretty important functionality (the popup didn’t display your existing bookmarks like the bookmarklet did). And even with del.icio.us, I still used browser bookmarks for quick access to the sites I frequent most via the bookmarks toolbar.

The new extension integrates with browser bookmarks almost perfectly—with a few big exceptions. It’s easy to import your existing bookmarks (the extension even offers to give them a special tag and mark them “private” so as not to clutter your existing bookmarks, as well as mines existing tags to try to categorize what’s imported automatically). The tag button is much more functional now and offers to show your existing tags, my big complaint about the previous extension. And the new extension nicely replaces the bookmarks toolbar and allows you to specify and even order your favorite tags, effectively replacing the last useful vestiges of browser bookmarks with a del.icio.us backed equivalent that also allows you to give other tags to those bookmarks.

That said, there are some pretty significant problems with the new extension, the biggest in my view being that there’s no way to change the sort order of the bookmarks within your favorite tags. Essentially, this makes the bookmarks toolbar far less useful—selecting “apps”, which used to contain a manually sorted list of web applications I frequently use, now contains a list of bookmarks in seemingly random order (it’s actually reverse chronological, but that’s not particularly useful for the bookmarks toolbar). The tags submenu under bookmarks doesn’t have any hierarchy to it—all tags are at the top level, making getting to a tag later in the alphabet quite tedious (I’d rather see a “tags starting with a”, “tags starting with b”, etc. structure). And, at least in my early experimentation, synchronization doesn’t always work as expected—changes to my local bookmarks seem to propagate back to del.icio.us, but the reverse doesn’t always seem to be true.

Still, it’s a promising start, and I’m going to keep using it. If they don’t fix the sort problem soon, though, I’ll likely revert to Google Browser Sync. (Interestingly, Google Browser Sync is listed as incompatible and is disabled on installation of the del.icio.us extension, even though it technically does other things, like synchronize cookies and passwords. This would seem to be a smart move on Yahoo’s part—challenge Google’s foothold in the browser and create a foothold of its own.)

A few parting thoughts: I’ve only installed this extension on my laptop thus far, and it’ll be interesting to see how well synchronization of my bookmarks works across machines (will it synchronize my favorite tags etc., allowing me to maintain a consistent browser toolbar? etc.). Finally, I’d like to see the “tag” function better integrated with the browser, perhaps the way Flock does it (a Google like star next to the address bar that reflects the current site’s del.icio.us state).