I ahve a few things probally very coomon things though not sure LOL
The first thing is the plastic contianers which has 3 sections for formula, so when going out you prepare the amount of formula needed heat up the water and shake into the bottle and walah a instant bottle without having to cart the whole formula tin about about $10 or som i think the are and a few different brands of these from Kmart/Target.
(we used to ahve it set up all the time was great for during the night when you are dead tired and dont want to be measuring the amounts of formula)
The other thing we also had was a plastic thing for the bath for newborns to lie in to save your back from aching. We had our son in plaster so didnt get to use the baby bath for longer than 2 weeks and we brought this plastic bath seat which suctions onto the bath and the bub lies in it with a thing so the cant slip out between there legs we found this great!
We have told everybody about both of these things i even brought thim for a gift as i used these two things religously.
DS 21-04-04 & Due 16-11-06