Hi Krista,
My family and I recently were able to dine at
Be Our Guest Restaurant for dinner. It was a lovely experience. I will say that I did make that reservation 180 days in advance, and when I called, there was one dinner reservation available at Be Our Guest Restaurant for dinner for the week that we were at Walt Disney World.
When we checked in for our dinner reservation at Be Our Guest Restaurant, we did see that there were cast members there to handle people canceling reservations and looking for same-day reservations. You can always check at the restaurant the day that you are looking to dine; however, I think that the chances of getting a table this way are not very good. I would suggest that you keep checking online to see if any openings come up from people canceling reservations. You can also call 407-WDW-DINE (407-939-3463) to speak with a cast member who can help you look for openings.
Also, do consider dining at Be Our Guest Restaurant for lunch, when it is a quick service location and does not require reservations. I have also had the opportunity to do this, and the food was quite good, and the atmosphere is just as magical as it is at night. If you decide to eat there for lunch, try lining up before the restaurant opens for an early lunch. This should keep your wait time down a bit.
I hope that this information helps, Krista! Please do not hesitate to ask if you have any further questions.