A blog-search widget. Used by Seth Godin. Nice interface pops up a lightbox on you page w/o taking the user away to do a search or browse the search results page.

I'm really liking Rob's experiments with jQuery plugins to make fancy Faves widgets.

Quoted: Warning - this article may be dangerously confusing to non-programmers

FlickR badge - flash or html versions

Quoted: Flickr is almost certainly the best online photo management and sharing application in the world. Show off your favorite photos and videos to the world, securely and privately show content to your friends and family, or blog the photos and videos you take with a cameraphone.

Several competing commenting systems now floating around the web. Disqus can do javascript-only integration, so it's not limited to Wordpress and Moveable Type (as sez-who is).

Quoted: The blog commenting system Disqus picked up $500,000 in a series A by Union Square Ventures (Fred Wilson), Naval Ravikant, Howard Lindzon, Aydin ...

JS-Kit has been building some pretty usefull client-side widgets to promote user interaction on any website, without have to install additional server software. I like this model - now they've released a new scoring (think Digg) widget for content.

They also claim they will announce some publisher partnerships soon.

Quoted: Widget provider JS-Kit has released their latest widget this morning, Score. Score adds a thumbs up/thumbs down-style ratings widget to any page content, and then aggregates the data ...

Article on widget load time performance.

Quoted: A single line of JavaScript is what powers a lot of blogging technologies these days. Widgets, sharing tools, visitors tracking, advertisers. In many cases a single line ...