Even though WordPress works pretty well out of the box, there is still a number of optimization tips that can be accomplished to make WordPress function that much better. Vladimir Prelovac has done an excellent job describing ten optimization tips that you can use on your own WordPress installation. The tips and techniques range from optimizing database tables to implementing caching. There should be at least one or two tips within this article that everyone can implement on their own blog.
Here is a sample for you to chew on:
Tip #1: If you are expecting a Digg Front Page you are likely to exceed your current limit of maximum concurrent MySQL connections which is among the prime reasons a site failing a Digg traffic spike.
You can prepare by increasing this number to about 250 using this line in the config file.
max_connections = 250
Check out the full list here (10 Best Tips For WordPress Optimization)