I couldn’t find a WordPress widget that produced output similar to del.icio.us’s linkrolls script. (You can just put their script into a Text widget, but its output doesn’t always mesh well with WordPress themes – it hardcodes h2s, and so forth.)
The Automattic example widget came close, but was a bit lacking on the customization front.
del.icio.us for WordPress also came close, but I disagree with having your server fetch the RSS feed, instead of using the perfectly good JSON API.
So I took the Automattic widget, hacked some extra features into it, made it configurable, and you can now see it in my sidebar. Well, footer currently. It’s a theme thing.
If you want it yourself, here’s the link: del.icio.us plus