Never refuse hand-me-downs, unless you absolutely know you won't be able to use it.
Cloth Diapering. Just buy about 3 dozen to start and you'll save HUNDREDS from not having to by disposable ones.
Breastfeeding. Not only is it healthier for your baby and creates more of a bond between the two, but it'll save from spending so much on formula and bottles.
Garage sales. You can get awesome deals here, and lots of times the stuff still looks like its in perfect condition. Why pay over a hundred for a highchair when you can get one just as good for 10 bucks? Sometimes you can find some kick-butt maternity stuff there too:)
Second hand stores - They're everywhere, AND they're cheap. And most have some pretty cool clothes that you could never tell are secondhand.
Homemade baby food. Yep, just make it yourself. Its just as healthy for your baby as baby food, but cheaper in the long run. I've heard if if make large quanities and freeze them in ice-cube trays w/ something over it, it works really well:)
Try to find a local Headstart. They are awesome and are cheaper than most daycare centers.