I have tried the usual methods - no usable results. The person I am
seeking has an email account somewhere in the UK, is a science teacher
or used to be. I have researched the friendsreunited.co.uk site with
no luck. I have a name, occupation, location and college attended.
Short of hiring a private investigator, what else can I look at on the
web?

While you said you have tried the usual methods, I still have to ask:
Have you tried looking him up in the phone book?

http://www.ukphonebook.com/

http://www.infobel.co.uk/

I forget which one, but at one of these you can do a nation-wide
search.

192.com have the electoral roll.