I've been developing in lot's of other languages, and never had this difficult a time setting up.
On a XPSP3 machine, I have WAMP in the root folder, with all parts installed. Then I have eclipse-helios for php installed as well.
My file path is C:\www\HelloWorld\hello.php
The follow code renders as a page fail inside eclipse and blank in my browser. In fact, "view page source" only shows me the html tags - the php lines are entirely missing.
There are lots of things that could be wrong but for starters, your module has to be recognized as a PHP module by the (WAMP) server. Thus, it has to have a .php suffix. If that is correct, I would verify that the content of the module is what you have shown above. If not, I would take Eclipse out of the equation initially and just use a text editor to save the module and try to run it in WAMP. If that works, then WAMP is ok and you have some sort of problem in what you are doing with Eclipse. If WAMP has a problem, then I'd fix that first and then sort out Eclipse.