Craigslist has a nice feature where when you respond to a poster you respond to an email such as job-fepsd-1120347193@craigslist.org. The email is then in turn directed to the real email.
I am looking for a couple pointers on how to do this with PHP.
Thanks,
Levi
This is usually done by piping an e-mail address (often, a catch-all address) to PHP. Here's a tutorial on doing it that should get you started in the right direction.