While working with SSL certificate based authentication I developed a handy tool to display the contents of certificates. Both PKCS12 .p12 certificates (commonly used for client authentication) as well as standard public .cer certificates.
And if you are looking for a couple of certificates to use to try this tool out, here is a PKCS12 self-signed certificate. Or, you could use my handy self-signed PKCS12 certificate generator and make your own.
Special thanks to John Veldboom for his ColorPal app which helped me make the more appealing to the eye.