If you are bothered that you can’t create html signature in Gmail or other web-based email accounts, WiseStamp could probably be the answer to your problem.

WiseStamp is a Firefox extension that allows you to create and insert rich HTML signature for your Web-based email accounts, including Gmail, Yahoo, Hotmail and AOL mail. After you have installed and get it running, you can create your own signature with a rich text editor and optionally, fill in your social network detail and get them to show up in your signature.