Per Persson

You can encrypt documents using a public key. The key owner can then decrypt the documents using the corresponding private key.

In the version with square root, the second term will be so small that one could actually round the first term instead.

By the way, shouldn't it be numbers.push(newNumber); instead of numbers.push(newNumber[i]); ?

How do you get phpinfo() with that code?

If you combine it with nohup or screen, you can even log out without the program being terminated.
http://en.wikipedia.org/wiki/Nohup
http://en.wikipedia.org/wiki/GNU_Screen

Why do you have an array of return values?

Note that with the above code you don't need to have the getreturn() directly after the call that returns the value, but you can get the return values later in the chain:
$test = new Chainable('Test');
$test
->baz() // call 1
->baz() // call 2
->foo() ->getreturn($returnvalueofcall2)
->foo() ->getreturn($returnvalueofcall1);

During reading this article I got a feeling - rather than a clear memory - that I sometime, more than ten years ago, had seen a way to make Linux itself recognize files as executable.

Here you can see how to do:
http://www.kernel.org/doc/Documentation/binfmt_misc.txt
Specific for Java:
http://www.kernel.org/doc/Documentation/java.txt