My understanding is that one can still get Sygate PF from the mirror sites such as Tucows. I got my latest installation from there in late Feb of this year.
I'm curious as to the licensing situation in this case. From my limited experience the software license normally allows unadulterated free distribution (ie one can share the software but mustn't charge a fee or modify it). I could not find the licence agreement for Sygate to check the situation here, but maybe copies of the firewall before Sygate was bought out could still legally be distributed??? Its not as if firewall software needs anywhere near the level of ongoing support as say a anti virus package.