Here's a great way to get a deal on diapers. Today's Plum District deal of the day is a $40 gift certificate to Diapers.com for $20! That's half price...and if you spend another $9 at Diapers.com, you'll get free shipping. Sign up today for access to other great deals, too! (This 'steal' is sold out for today...but you can still click on the link and sign up for more great deals coming up!)
Another site with similar great deals is Groupon. This site also features a deal of the day (if enough people buy in) in your area. If the deal is an online deal, then you can also buy deals based in other cities. The deals are only good to buy for one day on Groupon then each deal may/may not have a time frame to use.