Lesson Learned from Contracting, Revisited - SQL Server Central (requires free registration, sorry about the annoyance)
This is an excellent article looking at contracting/consulting from an experienced consultant's perspective -- without being anti-business in favor of being pro-consulting.
Contract consultants, a role I've occupied fulltime many times in the past, fill a need. Sometimes, they seem like a quick solution to a difficult problem. Hiring/managing consultants is most certainly not the same art as managing internal employees.
I've known complete dweeb consultants, charging ridiculous rates when they couldn't figure out VB6 dropdowns on their own. On the other hand, I've known consultants that really twinked my noggin, gave me a new perspective on things. Unfortunately, we're not all in the latter category, and far too many businesses have had bad experiences with the former.