In view of Ancient Mariner’s location in the U.K., maybe it is fitting that I suggest that you read Spycatcher, written by a former Assistant Director of MI5, Peter Wright. It’s a fascinating account of his involvement in the world of spies long before the technology that is currently available. Even so, what they could do back then is interesting in itself.
Another suggestion I have, and one that is more to the point of what you’re looking for, is to look into “social engineering,” as it applies to the world of computer security. In fact, Wikipedia has a pretty good summary article about it (http://en.wikipedia.org/wiki/Social_engineering_%28security%29).
Finally, SillyPoet, if you are anywhere near Washington, DC, make a trip into town to tour the International Spy Museum (http://www.spymuseum.org/). It’s very informative, and they have a gift shop that sells all kinds of things — including an excellent book called Handbook of Practical Spying.
And Spies Like Us is a lot of fun, too.
Here’s wishing you success in your quarterly espionage missions!