Driving to A-kon

I found that a trip between Houston and Dallas used up 5/6 of my tank. That means the trip to and from A-kon 2008 costed me $35 one way, or $70 both way. I wonder if there's a cheaper way to go to Dallas.

By the way, it turns out that 4 hours driving is not too bad if you pick the right thing to listen. On my way from Houston to Dallas I chose Podcasts, which doesn't work too well. But when I drove back form Dallas to Houston, I listened to Harry Potter Book 7 audio book, and it was proven to be a fantastic choice. I was attracted by the story and the drive felt much shorter.

Of course, the 12 pack of Coke that I brought before the trip also helps a lot.