I didn't think Macs entered the blue screen of death...
...but mine somehow managed. :
Removing the battery and disconnecting then reconnecting the power got it back to a place where it would reboot.
Not happy about losing my work, though.
PSA [United States]: Border documentation
Today is the first day Bermudian, Canadian, and United States citizens must show "documents that comply with the Western Hemisphere Travel Initiative (WHTI)" in order to cross into the United States either by land or by sea. : http://www.getyouhome.gov/html/eng_map.html
provides a list of compliant documents.
In practice, this means a passport or other similar document. Earlier requirements which allowed American and Canadian citizens to cross the border with ID and proof of citizenship have now been superceded.
More information is available at http://www.dhs.gov/xtrvlsec/crossingborders/