E-Mail Icon Generator is a small website utility which creates an image of your email id. You can use this image of your email id on your website, blogs, email, signatures, etc... This will certainly help you avoid unnecessary spam when you are posting your email in public.

Example:

E-Mail Icon Generator lets you create a badge with your email address.

The icon can be used to link to your email address on web sites, blogs and forums, for example.

E-Mail Icon Generator supports Gmail, Yahoo! Mail, Hotmail, AOL address and a few other domains.

You can download your own copy or use an icon generated by E-Mail Icon Generator as it is used.

Use only the icon (and no mailto: link) to prevent spammers from collecting your address.

Check Email Icon Generator here.

I know this is an old service (Since 23rd June 2005) but it's still running good.