Are you already having trouble preventing your enterprise Wi-Fi clients from connecting to some of the existing public Wi-Fi networks (e.g., T-Mobile, Google WiFi)?
Guess what - the latest Palm Pre Plus or Pixi Plus can be converted into a cool mobile hotspot. One can easily roam around with this pocket hotspot. (http://www.nytimes.com/2010/01/21/technology/personaltech/21pogue.html)
It is amazing as to how some of these cool technological advances can create new avenues for attacks. Suppose an employee or a visitor wishes to sneak-in a hotspot or a honeypot AP into your enterprise. If you are paraniod, you can possibly think of frisking him for an AP (before allowing him into your premises). But, can you go to the extent of preventing him from carrying a Palm into your enterprise?