I've read almost every link I've found on constructing homebrew antennas; pringles cans, coffee cans, etc. I even read the http://www.turnpoint.net/wireless/has.html
link that compares different types of cans. What I'm interested in is given your personal experimentations with external attennas, which you have found the most usefull
Now, just because a particular type of can might give you the greatest range, it might be akward walking around the office parks with a 500 gallon drum you've constructed an antenna with and stapped onto your back with industrial strength nylon. So, from a corporate network security persepctive, if your mission is to seek out and SPECIFICALLY isolate where wireless access points lie - which can/antenna do you think is best suited for the job? The goal is to be able to essentially "point and click", and find/walk up to rogue access points.
I'm inclined to think a can with a narrow diameter is best suited, so that it may be "aimed" more accurately. The last thing I want to do is walk around 9-some odd, 30+ story buildings..."guessing" at where rogue access points are located.