Do you really need a reason to eat pie? Well I've got one for you. Sunday, March 14, 2010 is National Pi Day, a celebration of the number 3.14, which is useful for passing geometry class and getting free pie but not much else. Restaurants use the pseudo-holiday as a good excuse to giveaway free and discounted pie to drum up publicity.

Me, jaded? Not while I'm eating free pie.

Marie Callender's is giving guests a free slice of pie with purchase of an entrée this Sunday. Marie Callender's has more than 30 different pies, including apple, banana cream, chocolate cream, coconut cream, pumpkin, lemon meringue, and razzleberry. Cheesecakes are excluded. MC's is located in 10 western and south western states.

Bill Johnsons, a small chain in Arizona, is selling whole pies for $.99 this Sunday. Wow!

Petsi Pies in Massachusetts, is giving away free "minute" pies starting at 1:59 p.m. Sunday. You can also get a certificate for four whole pies if you can recite the first 100 digits of Pi.

Whole Foods is selling pie slices for $2 to benefit the Whole Planet Foundation and is selling whole pies for $5 all day Sunday.

Morton's Steakhouse is selling slices of key lime pie for $3.14 all day. The slices normally go for $10.50, which is insane. They are in located in 27 states and Puerto Rico.

Even Edibile Arrangements is getting in on the frenzy. They are giving away free samples of fruit dipped in chocolate, according to their Facebook page.