SignatureSatori - A Solution for central e-mail signature management for Google Apps.
WiseStamp - WiseStamp allows you to easily create and implement slick and unique email signatures for your business.
Signature Lab - Create a beautifully designed email signature in seconds.
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.
Signature.email - A powerful visual drag and drop email signature generator paired with the easiest way to maintain consistency for your whole team.