Well, one can say that they're "strategically placed". Here's the ones I've gotten cash out of:

NRT
Ginza (Apple Store and Nissan Gallery!)
Shibuya
Roppongi Crossing (great for gaijin who drink)
Both Shinjuku Branches (ramen at one, books at another)
Makuhari Messe (big convention center in Chiba)
Akasaka
Shinagawa

These are either all business centers or places that are popular destinations. Of course, I'd appreciate it if Citibank were to open some ATMs in Asakusa or in the Shitamachi area, but since I'm going to these places ANYWAY, it's nice to have cash handy... ^