Below are some great sites for creating free email signatures. Please note that some sites may include ads into your signatures so please be aware.

Please remember that free email signatures are not tailored to your business and thousands of people across the world will have the same email signature.
At E-MailDesigns.com we create a unique professional email signature to match your business's brand and identity.

http://www.createsigs.com - Automatic Email Signature Creation
http://www.my-email-signature.com - Free Professional Email Signatures
Google Directory - Provides many sites that have free amateur signatures
http://www.signaturegenerator.net - Free Email Signature Generator for you to put on website's.
http://privacysig.com - A similar service to above.