Firefox/Feature Brainstorming:email
Email Address Handler
Currently, whenever an email address link (e.g. mailto:example@example.com) is clicked, a message is composed via the client's default email application (Thunderbird, Outlook, etc.). A better feature would be for the Firefox browser to overload this feature with the ability to trigger a new email to be composed through a webmail application as well (Gmail, Yahoo, Hotmail, etc.). This feature would work similarly to the RSS reader feature inherent with the latest versions of Firefox, which allows you to subscribe to an RSS feed via multiple services.
The handler would also give the user the ability to send an email through their default client application, and depending on their profile in Firefox, they would be able to specify a default email provider.