I'm using W7. This will probably work on Vista as well. Thanks to Kevin for helping me figure this out using Buzz (which turns out to be a little more productive than Wave (which I thought Wave was designed for)). Buzz allows many of our friends to read our conversation but I thought others might want to see it also.
My netbook already launched GMail when I click on mailto links but my desktop did not.Somewhere along the line I'd set the netbook to do this, but I couldn't figure out how.
Google suggests using Notifier but if you're using Chrome perhaps you're already using an extension for that. Notifier isn't a resource hog, but I don't need over redundancy.
This MS Help site: http://windows.microsoft.com/en-US/windows-vista/Change-the-default-e-mail-program
Tells you to go here:
Control Panel\Programs\Default Programs\Set Default Programs
To designate default actions for programs and file types. There you can set Google Apps defaults, including MAILTO links on the web. You still need Google Apps installed, but that gives offline email which is something I want and already use. While you're at is, why not install Google Pack (which includes GApps) and let it handle package management for you? You can ignore the Spyware Dr w/ AV and install Security Essentials which is free and runs on XP and above Windows clients.