Interested in buying investment/commercial property (both investment
and residential) using a real estate option contract. But I'd also
like the ability to sell the contract to another party before it
expires. Are property option contracts scams? Or are they legitmate
way of buying/selling land/property?  Is there a source on the web
which provides details on conducting business this way? Thanks

From these two sites (and there are others), it seems that real estate
option contracts are an established and ligitimate way to to buy and
sell property, and also that they may be transferred to a third party:
http://www.humanresourcesupply.com/optopurreale.html
http://www.dignitymortgage.com/Creative/Buying_with_Option_Contracts.htm

Of course, this is no legal or professional advice.
Myoarin