I got the same call tonight.  He said "We are not a scam.  We are just going to show you simple things you can do yourself to save energy.  We are not going to try to sell you anything."  But then he says my wife and I both have to be home "for tax purposes" becuase of the federal rebates.  I'm not stupid.  They are going to try to sell me something and need both of us there for the contract to be binding for an in home sale of something for the house.  He gave me the same website.  It is for companies selling solar products.  Clearly they are going to come and try to sell you solar products.  Don't let them come to your house.  Any business that misleads people like this to get in the door cannot be trusted.