Anti-Splog Not Going To Work

That's kinda lame that anti-splog is not compatible with buddypress as I learned from this post:

This entire site seems to indicate everything is buddypress compatible. I mean isn't that the whole point? Also, I was under the impression that anti-splog stopped spam registrations (fake user signups). If it does not do this could you please let me know? The other thing that kinda sucks is that it is only allowed on up to 10 sites. We will eventually have many client sites in our multisite network and we advertise that spam will be completely taken care of. If anti-splog is only available on 10 of those sites, it won't work obviously.

Could you give me a better recommendation then to block spam registrations? Or is there a way that I can use Anti-Splog for all my sites? I really really want to be able to use it.