Aurora: there's no "but" about it :) We have been dynamically analyzing sites since most solutions were thinking about making the distinctions between domain and URL :)
Our proxy performance is something I am particularly pleased with - recently we seem to have been ahead of the proxy sites, and manage to pick them off with content and certificate analysis before they start.
Of particular interest:
BeyondBlox46 a Free Proxy Site is new today, but of course is taken out by the content filter immediately.
Further edit: Aurora, I may be *completely* off-base here, but would it not be prudent to let folks know you are in IT Sales rather than a School Network type. Something subtle (like my sig!) would help let folk know where you're coming from. Apologies if I misunderstand your profile!