Thanks for all of the advice everyone -- quick question. Has anyone re-booked at the airport?

It looks like I'll need to cancel/rebook a flight in July, and was wondering if it's just easiest to do it all at the airport (cancel and rebook), or do the cancellation online, and bring the info with me to the airport (I could see this being more complicated possibly).

I don't live very far away from the airport, and it looks like I could save the $30+ on PUF, so that would be nice.