Actually, a better idea would be to dissipate some of the energy from a cloud, *without* an actual lightening strike. This is basically what Ben Franklin did. (I'm about to dispel the myth you learned in 2nd grade.) Ben Franklyn's kite was NOT hit by lightening. Rather, a current ran down (or up) his string, which he noted by placing his knuckles close to a key on the string.
This can easily be demonstrated with a van de graff generator.. If you slowly bring a charged needle toward a charged van de graff, you can start bleeding off a current without having a spark strike the needle. In my class, I can use this current to operate a simple little motor made out of 2 liter bottles and aluminum foil.
Hmmmm.....
Anyone know how many beer bottle capacitors it would take to hold 10^10 joules?