What to name your CSS Classes?

So you just put together your awesome all-div layout. Hot. Now, before you think, you're done... you may consider your css id/class names. Did you really just name your footer div's class "footer"? You did? Oh ok, well... how important do you think that sounds? And better yet, does it relate to anything on your site? (If your site is about football/soccer, then perhaps you have an argument). Try naming your classes and ids something more meaningful to the scope of your site, or even terms that don't scream "I am useless." "maincontent," "importantinfo," "goodlower," "greathorizontal," are all better than "main," "userinfo," "footer," "sidebar"... etc... Just an idea...