Using a power kite on land can be the biggest buzz since kitesurfing and tends to be a little cheaper and more easily achieved than for kitesurfing.

Land kiting can be experienced in a number of different flavours;- 

Mountain boarding is the use of large rough terrain skateboard like boards with rubber pneumatic tyres to allow riding on a variety of surfaces.  Mountain boarding is so closely related to kite surfing that learning one will help immensely with the other. 

Kite Buggying is the riding of three wheeled buggys whilst being towed around by powerful kites.  Buggys can handle a wide variety of conditions and can reach speeds of around 100 km/hr.  Buggying can also be quite three dimensional with the adding of a seat belt to keep the rider in the seat whilst boodting huge jumps in the buggy.

Snow kiting is using a power kite to tow you around on either snow skis or a snowboard.  This doesn't need a mountain and flat fields of snow suddenly become epic playgrounds.   Big air and crazy tricks similar if not same as kitesurfing are the norm in snow kiting and is probably the fastest growth area in power kiting at the moment