Saved for later... Diaper Bag stocked up with...

Extra clothes... seriously 2-3 extra outfits/onesies

Diapers, usually around 8-10 at any given time. I'd rather have overkill on this. Diapers rip too, and that's a headache if you don't have back ups for the back ups. (we use disposable in the diaper bag)

Blanket/changing pad that you can put down anywhere to change the baby on.

(usually around 6 mo) Bibs, also disposable for the diaper bag. Think "Bibsters"

(usually around 6 mo) Table covers, again, disposable. These are great, especially when the baby starts eating cheerios, etc. when you're out and about. The highchairs and table tops at restaurants... ewwww. This made me feel better about the kid eating right off the table.

Bottles. If breastfeeding, it's still not a bad idea to have these. Put the breastmilk in a cooler in the diaper bag, pour as needed. Toss whatever's left when you get home and re-set the next time.

And if not breastfeeding, aka using formula, a nice trick we picked up was pre-measuring the formula powder in the bottle, and loading those in the bag. Then having a few extra baggies also preloaded with the powder. All you'd have to do is add the water, shake and serve. But didn't have to worry about spoilage. Use when you need kind of thing.

If you want to cover up while BF in public, then toss one of those in the bag too. (I personally didn't bother with the cover. I found it to be more of a pain to use then to just do what I needed to do)

Wipes! You can NEVER have too many wipes. Seriously. Mouth, nose, tushy, etc. They're wonderful.

Paci's if you'll use them. Extras are nice to have.

Empty gallon size ziplocks. Usually about 10 each time. They hold used diapers, soiled clothes, used bottles, etc. They're wonderful.

Hand sanitizer (more for you), lip balm, nipple cream, and hand lotion.

Some small toys (rattles, teething rings, etc).

baby carrier - Beco, Ergo, Moby Wrap, Bjorn... what ever one you're using, nice to have in the bag for when baby needs to be worn.

first aid/medications like baby tylenol, and band-aids. You never know and can't be too prepared.

rubber bands. Yes, rubber bands. They come in handy when you need to quickly baby proof an area and they don't take up too much space.