Haven't tried this but I don't see why it wouldn't work:

- throw your PHP into the header.thtml to be eval'd
- make sure the output is inside its own div in your header.thtml
- in your style sheet, set that div's position absolute (by way of a class definition and its corresponding CSS rule), which means that you can place that div anywhere on the page you want, including near the bottom of the page--you just need to make room for it because it will be "out" of the document flow..

See your local CSS reference sheet for how to set absolute positions.