JOI  Delibar does pretty much the same and it is free. Also has a version for windows.

http://www.shinyfrog.net/en/software/delibar/

Delibar is a simple del.icio.us desktop client for macosx.

Delibar collects all your bookmarks in the system bar, so you can access them comfortably.

Delibar offers you many of the del.icio.us features and a lot more, like:

Tag and bundle catalogation

Sorting entries by alpha or frequency

Recent bookmarks

Exporting in a html page

Bookmarks autoreload

Proxy support and auto detection  
(Version 1.6.7)

GLOBETROTTERDK  Is there a similar app that works with Google Bookmarks?  
(Version 1.6)

ESUBS  In the Age of Bloatware, Pukka is a real pleasure to use. It does what it says in a simple, elegant fashion. Stable as a rock, it makes posting to del.icio.us feel like it was part of the OS. Add that to a small memory footprint and Pukka's a bit of a must-have. All that's missing is the Joyent integration everyone is begging for, but I still can't take off a point for its absence. Top stuff.  
(Version 1.5)

RANDOMDUDE  My preferred way to post links to del.icio.us. Better than using the del.icio.us bookmarklet that sends you to their web site. I'm sure there's a way to hack this, but it would be cool if it would let you hide the dock icon, since you probably never need it.   
(Version 1.3)

ECHIDNAE  This is nice, but one thing I think is missing and should be included is that when you drag a url from an open browser window to Pukka in the dock, it should grab the name of the page from the browser and use it as the title. Apps like URLwell are able to do this, and I don't see Pukka should be missing out on that.

Overall, very nice app though.  
(Version 1.2)

PAUL_LITVAK  Great little app!

Integrates well with the web browser (I use Camino) using either the bookmarklet or a keyboard shortcut.

I love how it auto-completes tags and displays a Growl alert when items are posted.  
(Version 1.1)

MAIQUE  it works, it's free and, as someone said, the developer listens to the users.

while flock doesn't get to a point where i can use it without fear of losing something important or just taking a lot of time with every new tab, pukka is working on all of the other browsers and i add more links to my del.icio.us account than ever before.

it's as easy as could be and works flawlessly.

thanks.  
(Version 0.9)

MISTERCHARLIE  Excellent. This is much faster than using the regular bookmarklets fro posting to del.icio.us.

Simple, slick, all keyboard-able (is that a word?). And the sound effect makes me laugh every time (although don't worry. You can turn it off).

Developer seems to be listening to his users, although he's keeping this ting small and focussed too.

Whatever. It's free.  
(Version 0.9)