Using fire...

http://www.millenicom.com/~davec/Jeep/Pitts/2001/TireInflation2.mpg

Here you can notice how at the end of the video a guy uses a CO2 tank....

Another video:
http://24.248.84.138/hummers/videos/Tire.WMV
_________________________
Regards,

Abiel
www.abielg.com