On New Years Eve, one of the best things to do is to stay downtown off the river walk. The clubs are booming, there are bands playing downtown, and then at midnight there is an elaborate fireworks display.
During the day, down the river walk, there are vendors and artists. There are several gift shops with unique items and several restaurants to choose from. One of my favorite restaurants is La Margarita, which is downtown, in the Market Square. On weekends, there are usually mariachis, and live bands.
Quick Tips:
If you are going to visit San Antonio, you will need at least a week to see and take everything in. A rental car is a must! The best time to visit San Antonio is in the Spring, or in the Fall. The summer months are pretty hot and humid. However, if you can bare the heat, the sights are still beautiful. Don't forget your camera, and plenty of film, becaue San Antonio unique, and no other city can compare to it.
Best Way To Get Around:
A rental vehicle is the best way to get all the sights in. If you plan to be there just for a weekend, and are staying downtown, then I recommend walking and/or a taxi. There is a public bus system called the Via Via, and it goes through out San Antonio also.