I've been putting off renewing my passport since I haven't had any plans to go out of the country within...oh, the past TEN years. On top of that I was literally at the cut off for being able to renew your passport in the mail (date of issue has to be when you were 16 years or older, and I was 15 at the time...). I called around to four different locations that were nearest to me and two of them didn't have any appointments until a month out and the other two didn't pick at all.
Luckily I looked up the website for the U.S. Passport Acceptance Office at ASU and it's a walk-in basis Monday through Friday 9am-3pm. I decided to head over around 10am just in case I had to figure out where the office was since I'm not at all familiar with ASU. It actually wasn't that difficult to find despite the fact that I couldn't see the suite 111 number at all. They have three complimentary parking spaces that are first-come, first-serve that are right across from the actual center/the reserved spaces for patients for the SKI Vascular Center.
The office is small, but was pretty much empty when I got there. I only had to wait for a few minutes before I was helped. I had everything ready (with extras) to make sure the process was as painless as possible. The person who helped me was so nice and gave me on advice on what to do since I had a trip planned for exactly 6 weeks out. I ended up choosing for the expedited service which does cost more, but ensures that my passport will get to me in 2-3 weeks. (You have to write a check for whatever passport service you're getting, then pay with either a credit or debit card for the ASU processing fee (mine was $185.45 + $50).
Overall waaaay easier than I expected this process to be. A+++