I get mine from Albertsons. Vons also delivers but I didn't like their website as much for ordering.
They say 24 hours, but I've gotten them in about 16 or less.
You give them a 1 1/2 hour window when you want them delivered.
Dub,
I tried to tip the guy first time and he pointed to the part in bold that said no tips. I haven't done it since. Believe me I would tip these guys as they are busting their butt in this heat and carrying crates of groceries upstairs to me.
It is the store itself that delivers it. Probably depends on your area who delivers.
Go to website, shop for the stuff you want. Like someone said, you can save it to a list. I end up putting a bunch of stuff in my shopping cart and then editing it out until I get down to the amount I want.
One big advantage is if you want to spend say $200 on groceries, you can completely control that. If you went to the store, you would have to guess or walk around with a calculator.