City Museum is Awesome
Take a walk around East St. Louis (kidding)
Did you know that St. Louis is the backdrop for the upcoming Resistance 3 on PS3?
http://www.missourah.com/2010/09/29/new-video-game-resistance-3-features-postapocalyptic-st-louis/
If you come downtown and find the Schnucks Culinaria, it's right across the street from the Old Post Office, which is in the 2nd concept art pic in that link.
I've been to Vin De Sette (sp?) a few times, and it was pretty good.
I have to 2nd EITS comment about Scape. That place is awesome. My brother and his wife threw a dinner party there. We had about 25 people. The chef came out and spent nearly an hour going over the menu with us, giving us samples of different pastas, sauces, etc.
It was kind of expensive, as the "cheeseburger" I got their was about $18, but man on man, was it good. It was actually worth it. You can also hit up the Drunken Fish, which is just down the street from Scape. It's basically a sushi bar.