Besides the beforementioned New Hampshire, almost all swing states have been either inching towards Obama, or at least inching away from McCain.
The top 4 closest battleground states are now all lean McCain, with New Hampshire with a margin of only 0.5%, Virginia with a margin of 0.7%, Nevada with a margin of 1.6%, and Ohio with a margin of 2.1%.
Indeed, for the first time a quite a while, no Obama state has a margin within 2%, with only two states with a margin within 3%, Colorado and Pennsylvania. Indiana and Florida also have a margin within 3%, on top of the 4 other states already mentioned.
So, to round it up:
For states within 1%:
McCain 17, Obama 0.
States within 2%:
McCain 22, Obama 0.
States within 3%:
McCain 80, Obama 38.
And while I mark my Too Close To Call margin at 5%, I think 3% may be closer to the margin of where a candidate needs to be if they want to legitimately have a shot at picking off a state on election day.
Note:
I should include that this doesn’t include this morning’s Mason-Dixon Florida poll, since I don’t have info such as number of respondents and margin of error, but it’s quite possible that after that poll, Florida will make it a complete top 5 for McCain as far as closest states go.

