If you're into trains it's a great museum, if you're not (like me) I wouldn't bother. Old Sacramento is pretty good though, and there's a nice trail that goes along the river if you want to stretch your legs.

If you need tips for things to do within walking distance let us know. I work about 5 blocks from the train station in downtown and there's plenty of great little eateries in the area depending on what you like. Hope you enjoy your time in Sacramento!