Change register URL to prevent spam signups

Hi All. I learned from an expert saying that spammers just google "register; create an account". Obviously, all websites powered by wordpress & buddypress are coming in the front pages in Google. So, to prevent the spammers and splogs from signing up, we have to take measures to change the default register URL. Could somebody please guide me technically?

I explored Anti-Splog plugin. Unfortunately, my specific feature is not available that is compatible with buddypress!

Thanks in advance,
Siva.