The Messenger Web Toolkit, which lets you offer Windows Live Messenger functions from within your blog, has just been updated to version 3.7, according to a blog post on The Windows Live Messenger Developer blog.

Changes include offering Offline IMs, and ASP.net Ajax Library integration:

Starting in V3.7, the Messenger Web Toolkit UI Controls are built as ASP.NET Ajax Library (http://asp.net/ajaxlibrary/) controls.  This means you can add MWT Controls to your pages using standard declarative and programmatic methods of ASP.NET Ajax Library.

Application contacts have been improved as well, and the Messenger Web Toolkit now works with more browsers, with added support for Firefox 3.6 and Chrome 3.

More information at http://dev.live.com/messenger

Documentation, including a change list

Windows Live Messenger Web API forum