Great question :) Mostly working on Stitcho.com ( http://stitcho.com ) Stitcho is a desktop notification widget for your website, with support for Windows and Mac. Add desktop alerts to your web app in less than 30 minutes. Also, trying to build an Erlang community in the DC area (search for Erlang on meetup.com) Finally, putting together a presentation for BarCampDC this Saturday.
We've been doing something like this with Growl - how does it compare?
Rather, Stitcho lets you send notifications from server side code that are delivered to your users via the Stitcho widget. The Stitcho server sits in the middle to route and deliver the notifications.
Also, Stitcho provides widgets for Mac and Windows. (The Mac version can use Growl if it's available.)
Does that answer your question? If not, please clarify.