Geek with a .45 has two posts about recent trends in Maryland and New Jersey to disenfranchise their own state by apportioning their electors according to the results of the national popular vote. This would break down the districting system created by the electoral college that forces candidates to campaign widely instead of narrowly.
It is a stupid idea. Fortunately, once Maryland and Jersey vote one way and the national popular vote goes the other, they will probably turn on their state legislatures and demand a return to some sort of state-wide apportionment system.
If you don't want to go all-or-nothing, then using Congressional districts is probably the only other serious option. I don't like it, because the President will tend to be of the dominant Congressional Party using that methodology, but it might work. The MD/NJ system is just foolishness.
UPDATE: NJ isn't as stupid as I though, their law is designed so it only goes into effect once the majority of electoral votes are determined through the national popular vote. Unfortunately, it also creates a multi-state agreement which, unless Consented to by Congress, is probably Unconstitutional. But hey, when did the Constitution stop New Jersey from doing anything?