I specially liked the idea of printing food. Not the glorious goal of ending world hunger(still need the ingredients right?) - but the fact that I won't have to drag my ass to kitchen. Write a cron job, that'll download recipe and print food!

* Desktop goodies/organization - paper inbox, laptop stand, pencil holders, phone docks, etc. If the material is strong enough (and the printers are big enough), I'd love to be able to print a cool lcd monitor swivel/stand (something like the ergotron.com products).

Hopefully in the future, the basic 3d printer will go beyond plastics and allow printing from some hardier durable material (nanotubes maybe), then you'll be able to pretty much download a design and print anything.

Think of situations where there are lots of varieties in the two interface points,creating enough combinations to make production of all of them economically infeasible. You can combine two "ends" and print a custom part.