The Gulf Coast road trip that my family and I recently took definitely helped me complete this goal. I got a picture of each state's sign/welcome center as we entered the state! It was hard at times, because you sometimes didn't know exactly when the sign was coming up and you had to have the camera poised and ready for a mile or two - and then you had to have a quick shutter finger to get the picture!
On this trip, we visited 8 states (9 if you count Virginia)! And three of these were new states that I've never been to (which helps me cross of part of another goal (#66)!
How many states have you visited on a road trip?