Ok I have said it before and Ill say it again, the meta description IS very important for your search engine optimisation efforts. Not because it will rank you higher, BUT it will distinguish your website from your competitors in the SERPs. Ignoring this tag, is plain stupid! Imagine you get a FREE ad in one of the most popular newspapers, would you ignore the content of the ad, would you bullocks! Rant over, but I’m sure I’ll bring it up again 
But sometimes you can follow the rules, writing unique, descriptive meta description tags for each page, but when you check the SERPs you realize thats NOT at all what you wrote. I bet you a bottom dollar thats because you have recently signed up to the dmoz or Yahoo directory and they are feeding your directory title & description straight into the SERPs. Bugger! But dont despair; there is a way out, thank god.
Now the NOODP tag has been around for a while, this tag tells the robots not to display the title and description from the Open Directory Project (dmoz). But until fairly recently there was no way out of the Yahoo! Dir description (I know people that stopped paying but still couldnt get out lol). But now Yahoo! has finally given us a way out, enter the “NOYDIR” tag.
Here’s links to the Yahoo Search Blog where you get examples of both codes: