Interestingly I was discussing this with some friends last night (trying to solve the worlds problems on the back of a napkin as always :) One suggestion was to try and crowdsource deliveries in cities, ie. have depots centralised around public transport areas. But how to deal with security?

Amazon.com also provides a similar service to their customers: delivery to lockers that are available at all hours:

http://www.engadget.com/2011/10/17/amazon-lockers-come-to-ny...