Quadcopters
Quadrotors
multirotors
types tricopters, quadcopters, hexacopters
they can be helpful as shown here:
http://www.youtube.com/watch?v= VIDEO http://www.youtube.com/watch?v=W18Z3UnnS_0 It can be a hobby with FPV (first person view) check out this guy's channel maybe this change some of your views:
http://www.youtube.com/user/juz70/videos?view=0 cost can vary alot with a simple quad being like:
[url]http://www.hobbyking.com/hobbyking/store/__27172__HobbyKing_Q_BOT_Quadcopter_Mode_1_RTF_.html
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and the more advance: (and this is still cheap)
http://onlyflyingmachines.com/product/ofm-450-v2-quadcopter-rtf/ bit more expensive but the application for this is Aerial photography:
http://onlyflyingmachines.com/product/ofm-650-v4-professional/