WiseStamp - WiseStamp allows you to easily create and implement slick and unique email signatures for your business.
NEWOLDSTAMP - Email signature generator
Signature Maker - Signature Maker helps you create digital signature online. Signature creator is a simple, fast and free tool for making custom electronic/email/font signature.
MySignature - MySignature is FREE Email Signature Generator that helps to create Professional Signatures for major email clients such as Outlook, Gmail...
Quicktext - Quicktext is an extension for Thunderbird that lets you create templates that can be easily inserted into your own emails.
HTMLSig - htmlsig.com makes it easy to generate email signatures without any HTML coding skills.