Blog Promotion via social bookmark services

These days everyone talks about the great benefits of social bookmark services. So why not use them for promoting your blog? Those sites accept every submission you make since in most cases they were built to keep your own bookmarks and share them with others. Of course you need some luck and really good content that other people add your site, too, but it's not much work and it doesn't cost a cent.
Most of the social bookmark services have Lot's of technical interested visitors which may be good if you're providing technical content.
The biggest of them are digg and del.icio.us. del.icio.us doesn't look very nice, but it's clean and simple and that's what i like pages to be. You can use some greasemonkey scripts to make it look nicer or to even add some functionality if you're using Opera or Firefox.
Furl and Linkfilter are a bit smaller and less known, but that means better chances of getting discovered for you.
You should definitely give them a try and see whether it works for you or not.