The claim to fame here is that this was the last stretch of I-40 to be commissioned. According to Wikipedia, that's because there were lawsuits about the route, which were ultimately settled when three Williams exits were designated. Once the road was completed through here, Route 66 was decommissioned the following year.
We did grab a decent lunch at a Mexican place, and we did take a stroll around to check it out. I'm including two photos of my favorite "sights" from this little diversion - the excellent Rod's Steakhouse sign, and the locomotive for the Grand Canyon Railroad.
One of the claims to fame here is that Williams is the town you catch the train up to the Grand Canyon, if you're traveling that way. It looks like a fun trip if you've got the time - our stop was mid-day, so I just took a quick walk over to the station for a look around.
Once we'd checked it all out, we headed back to Las Vegas for our last night. We had an early flight out, so we stayed in at the Tropicana - we were very well taken care of there after our disappointment with the first room. It's a nice facility, and I think we'll stay there again sometime.
If you want to know more about Williams, AZ, here is the Wikipedia link: