When we went without the kids back in 2002, we had no trouble getting into any of the restaurants without PS. I even ade some PS ressies before we left, ad some of the we never made it too, bt we walked into places that were more convienient along the way. We even found a couple of new places that I will be making PS's for this Dec. In my opinion, it WAS easier being just two people,though most of the tables in the restaurants are all the same size (seat 4) or very large for 4 or more people so it's not like there are alot of tables for two. Some that you might have better luck at ar those that do like:
LeCellier
Coral Reef
Donald's Breakfastasaurus (has a few tables for two)
Teppanyaki
Alfredos
Rose and Crown
Hollywood and Vine