Many other registrars offer free or fee whois privacy add-ons. If your registrar doesn't offer that option (most do), then you can transfer your names to one that does...
If you don't want to transfer your domains to another registrar then another option would be http://www.securewhois.com, however you have to purchase a domain registration with a private whois first for $19.95 in order to get an account. Then it's $9.95 a year for every domain you'd like to add private whois information too.
It'd be cheaper to transfer them to another registrar though as that option would be pretty costly. :tu: