Not much use outside the UK, but I'm sure there are equivalents elsewhere... I swear by Ocado, which is a company that delivers Waitrose (high end supermarket) goods - both fresh and pre-prepared - over huge chunks of England, cheaper than the supermarket sells it for itself, and easily orderable (is that a word) through an iPhone app or online. It has a 'delivery pass' product, too - delivery varies from free to £7, but the pass gets you a year of unlimited free deliveries - and reduces the minimum spend.

When I was travelling, this was a wonderful service - lovely food turning up on the door shortly after getting home (1hr time slots, too!) These days, it's still a wonderful service!