I enjoy spending time in Union Square but I especially enjoy it during the holidays because of all the lights and decorations put on by the different stores.  Another reason is to people watch and starting this week, you can watch or be watched at the Union Square Ice Rink.  It's opening on Wednesday, November 11 through Monday, January 18, 2010.  The hours of operation are 10AM to 10PM except on Friday & Saturday when it is opened until 11:30 PM.  Click here for information on rates and where to purchase tickets.  

With the opening of the ice rink, I feel as though the holiday season has officially begun in SF!

Picture via About.com