Part 2 of Way of the Spy is up on http://www.visual77.com/2009/05/the-way-of-the-spy-part-2-cp_dustbowl/.

This entry is about a prowling area on cp_dustbowl that I used to great success on defense. It gives you a good ability to keep their teleporter entrances disabled, stalk slower players and snipers, all while keeping near permanent cloak (except to attack/sap, of course).

Check it out, and keep an eye out for more Way of the Spy articles about locations that are beneficial to spies.