A few years ago I read this article with insight on what to do with extra paychecks.
Yes! If you get paid weekly or every other week (as opposed to monthly or bi-monthly... if so, stop reading now, this post will make you sad), and regularly budget based on 2 or 4 paychecks a month, then a few months out of the year, you will have an extra paycheck!
October 2009 has 5 Fridays. If you are a lucky winner of an "extra" paycheck today, the "bonus" Friday in October, consider sending it straight to your savings account, paying down debt, growing a down payment, setting it aside for holiday gifts, or splurging on that last-minute luxury Halloween costume.