Well, on food - Tesco and Sainsburys will deliver from their websites, and ocado.com for waitrose has been mentioned.
Pro - food comes to you and you only get what you want (not random hungry puchases).
Con - you have to be in when they arrive, unsure what the windows are.
Laundry - I was living in NE London at the time (about 3 years ago) so I used http://www.theironingboard.com/
There must be more of these around in other parts of town.
Pro - somebody washes, dries, folds and (optionally) irons your clothes.
Con - ????
(OK so it costs money instead of time, what you think is good value in this department is probably very subjective, and you have to be there to accept delivery, but they did deliver in the evenings :)
Cleaners are an odd one because you're allowing someone access to your property, often when you're not there. It may be best to find a trustworthy cleaner by word of mouth.