Two groups presented interesting antenna hardware in DEFCON last weekend. The Shmoo group premiered a gun-like WLAN antenna with a scope, dubbed "Sniper Yagi". The thing is supposed to be powerful enough to enable connecting to WLAN networks over 15km away. It also makes you look like a madman with an M16.
The Flexilis team presented a similar device for Bluethooth connections. With it, it should be able to connect to Bluetooth phones even if the owner of the phone is standing over a kilometer away.
Do note that antennas resembling assault rifles might be challening to get through airport security nowadays...