do it all

People who are really serious about software should make their own hardware.

-Alan Kay
Alan was right.
This quote came to mind recently on I project I'm doing the visual design for, but my company is not building. The development of the project is being done by another vendor.
I don't think splitting the design and development between 2 companies is a guaranteed recipe for failure, but it doesn't make me feel warm and fuzzy either.
Whenever possible, always execute the design AND develop of projects you're working on. Handling it all under one roof gives you no excuse for projects turning out wrong.