I did this when I was 22. Went directly from undergrad into my MBA...I had my MBA when I was only 24. Here's the catch: I went to a crappy school (now that I look back on my education) and now I am paying dearly for this huge mistake. Take it from me: if the top-tier schools want work experience, do it and apply. If you land yourself at a top-20 program, you'll be making six-figures in no time at all!