I had the same reaction. WTH are you going to make from the difference b/t IV's of the put and call of the same strike? I'd love to see the Optionetics sales pitch for that money maker. Although... you might be able to find some terrific put over call ratios where you can lock in huge wins via reversals - where you can't borrow the stock
IVolatility has (or used to have) a for-pay service called their "Advanced Ranker" that claimed to do this correctly. But when I actually tried it out, the information it yielded was garbage. Completely worthless. I wrote them an email pointing out what I had found, and they responded that they knew of the problem. So they knew their service was worthless, but were more than happy to keep it active and charge customers for information they knew to be inaccurate. I had the exact same experience with implied volatility for eurodollar options. They were calculating it incorrectly. I emailed them again, and again they wrote back that they knew of the problem. So be wary of data from IVolatility.
This link does not show skew but it may provide some info you find useful (it's also free) http://www.interactivebrokers.com/optionsCommentary/index.php?ib_entity=llc