[jQuery] jQ Validate Remote on blur()?

[s.ross]

I'm very happy with jQuery Validate, but am having difficulty with the  
following scenario:

    rules:
        "user[email]": {
          required: true,
          email: true,
          remote: '/signups/unique_email?lf=' + $ 
('.radios[checked]').attr('id')
        },

As you can see, this will (by default) issue an Ajax call after every  
keypress. The hash value onkeyup:false stops this behavior for all  
validations, but what I really want is to let all client-side  
behaviors take place on keyup, but the Ajax call only on change of  
focus.

Is there a handy way I'm not seeing to affect only the remote behavior  
as I describe?

Thanks, and thanks for this great plugin.