Imagine if there was a gadget that could disguise itself to look just like your favorite Wi-Fi hotspot, fooling your phone or laptop into connecting and enabling it to capture all of your personal data. Then imagine it cost only USD $90 and, being smaller than a book, could easily be kept hidden in public places. Finally, imagine a bunch of them were sold recently to hackers at a high-profile network security conference.

Yep - that's the Wi-Fi Pineapple. Should you be worried? Absolutely!
? More - WiFi Pineapple Penetration-Testing Tool Sparks Interest at DEF CON (eweek.com)
? See also - Introduction to Penetration Testing