I experienced the frozen dock / toolbar on my Macbook Pro running OS X Snow Leopard (10.6.8) for the first time this morning. Oddly enough, the only application I had running was Google Chrome.
I force quit Finder a fews times but the dock problem remained. All other aspects of the OS seemed to be working normally- Spotlight, hot corners, all applications, shortcut commands, etc.
After searching for a while on Google I found a solution that worked fast and, so far, permanently.
To Fix a Locked or Frozen Dock in Mac OS X:
Type the following line into Terminal (case sensitive):