Using the Gmail interface for our Google Apps install is great, but when it’s running in a Firefox window I always tend to accidentally close it.  By using Flock and Firefox together I can use one browser for communication (Flock) and the other for surfing / developing (FF).  Recently The Gmail blog posted this article describing how to set Firefox 3 as the default mail client when mailto links are clicked.  Below are some instructions to extend this for my setup so FF3 opens mailto links in Flock.  (Note: you need Flock 2..0 beta for this to work)

Follow the steps outlined in the Gmail blog here for your Flock install.

In FF3, Under Tools -> Options (Preferences on Mac) choose Applications

Search for “mailto”

With the Action drop down, choose “Use Other”

Click the Browse button

on PC choose “C:/Program Files/Flock/flock.exe” or wherever you have installed Flock

On mac, navigate to the Applications folder and choose the Flock application.

Now, when you click a mailto link in Firefox, it will open up a new window in Flock via Gmail or Google Apps.