Last year, the Firefox 3 added the option to associate protocols with web applications. A common way to create a link for addresses is by using the mailto: protocol, so you'll often find links to security@google.com.

When Firefox 3 was released, Yahoo Mail was the only webmail service that could be selected directly and the instructions to add Gmail were complicated. Gmail was added to the list of e-mails and applications is easy to define it as the client default email in Firefox and open all mailto: links in Gmail without installing extensions:

* Go to Tools> Options
* Select the Applications tab
* Search by email
* Use Gmail choose from the list of actions associated with the mailto protocol
* Click OK to save the settings.

If you want to set Gmail as the email client default for your computer and not just for Firefox, install Google Talk, Gmail Notifier for Windows or Google Notifier for Mac