Easily create HTML email signatures for your favorite webmail service
If you would like to use more than just plain text in your signature for your webmail account, give WiseStamp a try. WiseStamp is a Firefox add-on that gives you a rich text editor to create your email signature, and gives handy links to instant messaging services or social networks that you can add in to personalize your signature further. WiseStamp supports Gmail, Yahoo! Mail, AOL Mail, and Hotmail.