Here's a program I didn't know about until recently: AmazonPrime. I'm still on the free one-month trial, but I think I'll stick with it, as it's a great deal.
For $79 a year (about $1.50 a week) you get unlimited free two-day shipping, and you can upgrade to one-day shipping for $3.99. There's no minimum order size.
The nice thing is that a company or church could have one account, which would make the $79 almost negligible. But even for individuals, I still think it's a really good deal.