I don't trade VIX options but if I was going to, I might do a trade like this.
SELL -10 VIX 100 AUG 11 15 PUT @.25 LMT
I would sell 10 VIX August 2011 $15 put options for a $250 premium. The margin requirement would be $2354. This gives a 10% ROI on the trade if the VIX options expire OTM...