It appears Obama was for a gas tax holiday in 2000 when he was a state senator.
http://marathonpundit.blogspot.com/2008/04/obama-on-gas-tax-holiday-favored-it-in.html
http://embeds.blogs.foxnews.com/2008/04/26/obama-on-mccains-latest-scheme/
Ooh, good find - well done!
It would appear that in 8yrs, he has learned something and modified his thinking.