Do read this post from the Presentation Zen blog.
It is a follow-up to a previous post at the blog and mentions a presentation from TED on the "liberating effects of constraints." It also mentions a 2004 book, The Paradox of choice by Barry Schwartz, where he put forth ideas on how pursuing the maximizing of choice is not as liberating as one may believe but in fact is a cause for unhappiness.
Aah... don't we all ride the satisfaction curve!
Also read this Business Week article the post links to…
Creativity Loves Constraints ...but they must be balanced with a healthy disregard for the impossible.
…and a response to the article: Opportunities, Constraints and Barriers affect Creativity