PHP/Apache site owners may be interested in this post, which starts the ball rolling if you are considering sending a custom robots.txt to Phorm which is different to the robots.txt you want to send to Google, MSN, Yahoo etc...
http://www.badphorm.co.uk/e107_plugi...topic.php?7852
As I said on Badphorm, apologies I haven't had the time to fill in the gaps on this and release a script package. I'm sure others who know more about PHP than me will fill in the gaps if anyone needs a hand.
O.