Adding postback date to scripts?
<p>I'm writing some scripts that are free, but only to members within my teaching program. What I want to do is check what sites have installed the script.</p>

<p>I was thinking of obfuscating some PHP that posts back to my server when installed so I can see the domain it's used on. Obviously the user could remove this, but if I was to put a few application variables in with the code it might stop them removing because doing so would break the script.</p>

<p>Any comments on this approach?</p>
