打电话回家并删除“来电”代码行（跟踪使用代码的页面）

I created a php widget (one file) for free download, and I'd like to see it in action on the sites where it is implemented.

Is there any way to add a couple of lines, preferably packed, that will send me a mail with the host page url - and than remove this lines of code?

I'm not a php expert so it's all on guessings for now.

p.s.
Is that legal?..

• One file (with php, html, jquery, css. inside)
• Add lines to 'call home', obfuscated to prevent people bombard my email:)
• Once script runs for first time - send mail - delete lines of 'call home' code.

Instead of deleting lines from the source file you would create a Setup script to deploy the script and tell the user that you're tracking the installation so this will be legal.