I found another free clone of del.icio.us, yesterday. It's called Scuttle and is written in PHP instead of Perl (as is the case with Rubric, the code behind de.lirio.us/). Also, Scuttle is GPL'd whereas Rubric uses the Artistic lincense. As of version 0.2.0 Scuttle supports the del.icio.us API.
I'll probably try out Scuttle on this site soon, to find out how useful it is and how it works.
Steve Mallett has announced his new del.icio.us clone called de.lirio.us. The main difference between both, is that the (Perl) source code for de.lirio.us is freely available under the same license as Perl and it has a note-taking feature, i.e. you can add longer notes/posts to every URL.
I'm curious how successful it'll be and how it will compare to del.icio.us...
Also, there's a new block "My del.icio.us Bookmarks" on the right which shows the ten most recent entries on my del.icio.us bookmarks list.
After reading del.icio.us for a while now and being quite content with it, I decided I could as well get an account, too.
You can now view what I'm bookmarking on my del.icio.us page, del.icio.us/uwe. Have fun.
This rise of interest in the site may also be partly due to the recent slashdotting of the How I Feed My Cats with Linux article by Chris McAvoy, which has been listed on Crazy Hacks for some time now.