Okay, index.php is the main page of my site. polls/pollindex.php (renamed to avoid confusion) is my poll. What I want to do is have polls/pollindex.php displayed inside index.php.
Aaron, I'll do that if I have to, but it's a lot neater to have it in a separate file.
include and require aren't really working for me.

SSI is great, but are there any down sides to it?
Wow, the simplest mistake of all. I put <php? instead of <?php. It's working fine now.