Greenwich CT is not an easy market to penetrate. It has its own multiple lisitng service and outside brokers have to be members. Therefore you have to locate a broker that belongs to to that MLS. I can refer you if you wish.
I am an agent in nearby Darien which is a similar type of community and I can tell you that all real estate markets are not created equal.Altho our market is down considerabley, there are not really a large number of foreclosures...maybe a half a dozen in Darien for example. Also even at foreclosure prices you are dealing with twons whose average sale price is over $1.7 million so be sure you know what youre getting into.Contact me if you wish to discuss further.

A local Realtor can help you with lisats of REOs....they may also be able to help you with local auctions.