An inexpensive item is a heated unit that you put wet small cotton wipes in. Your baby will love the warm wipe and you will be able to wash and reuse the wipes.

Check the 99 cent store and the dollar bins at the Target entry for board books, toys, etc.--especially if you're travelling and need some novel toys to keep baby busy. Many 99cent stores also have produce (sometimes even organic) now. I buy the microwaveable veggie bags and use them all the time. We also use the farmers market (a real one--not the kind that sells 4 dollar gourmet chocolates!). You can't beat the taste/price of freshly grown tangerines!

Maybe this is unnecessary with OnStar and other similar services, and is more of a "Busy mom must have" than a "Cheap mom must have". My "must have" came about after accidentally locking my toddler, strapped in his car seat, in the back seat of the car. We were leaving a store on a warm day, and as usual, I set my purse under the dashboard, and tossed my car keys onto the driver's seat before buckling my son into his car seat. I didn't notice that he had discovered the door locks, and when I closed the door, I inadvertently locked him in. Had to call the fire department to get the door open, which they did by smashing a window, after unsuccessfully attempting to reach the locking mechanism inside the door.

Of course, I immediately stopped tossing my keys on the driver's seat, and I taped down the locks on the passenger side so they were less attractive to my son. But most importantly, I had a plastic "valet key" made at AAA, bought an inexpensive, but durable, pouch that could be velcro'ed in an inconspicuous spot on my car, in case I was ever locked out again. It gave me peace of mind to have the extra key available, just in case.

At the local party store right after a holiday or special event (Valentine's day, graduation season, ect....). Stock up on the clearance plastic party table cloths. They are great for dirty play (finger painting, play dough, and such). You can throw them on the floor under the high chair when the little ones are learning to feed themselves. Makes clean up a breeze and can be cut for smaller areas. I even keep a few in the trunk for impromtu picnics. At 2 or 3 for a dollar I can stock up for a whole year right after graduation season.

Seki Edge Styling Razor Haircutter, Tinkle Hair Cutter. Pretty cheap on Amazon. These two alone help me double the time between haircuts for me and my kids. They take regular razor blades from the drugstore too! I think I paid $15 for both. The Seki is adjustable and I like it for my son. I just comb my daughter's hair with the Tinkle cutter as normal and voila.

(note: I spent about $60 on other supplies to give full length trims/haircuts at home. But even without these, the Seki and Tinkle were great investments for the price)