Probably nothing more than the address of this URL http://americanresearchgroup.com/... This fascinating interactive site is pre-programmed with the results of the 2004 election by state, showing the elctoral votes for each state and indicating which party won the state. At the click of your mouse, you can "move" a state from one party to the other, and the new electoral vote total for each party will be displayed. This allows you to run any number of "what-if" scenarios.
So when you hear an analyst tell you that the Democrats cannot win the election should they lose Ohio, Pennsylvania and Florida, you could respond yes they could; if they can win New Mexico, Colorado, Virginia and Missouri.
That is a result that leaves the electoral college tied at 269 if no other states change. When the electoral college vote ends in a tie, the House of Representatives decides the outcome of the election, with each state delegation getting 1 vote. This means that the state will vote Democratic or Republican according to the makeup of its delegation in the House; as it happens, Democrats control 27 states and so would win a tie assuming every representative voted for his party's nominee.
This tool is useful for anyone keeping track of new polls as they emerge to see how the electoral landscape changes as more data is obtained.