npwsol - 3:47 pm on Jan 21, 2009 (gmt 0)

That is one way of doing it, and it is what the internets is best at.

To answer your question, it won't allow you to do anything special. You can change the contents of the image before you write it as output, but that's nothing special. Again, you ultimately have the just end-user's information to work with, no info about what site is referencing your stuff; also again, there is no benefit to embedding the code directly in the images (especially if you remove them from the root directory of your site).

Also, we're talking about PHP, which is a decidedly server-side scripting language. That means YOUR server-side.