Wharton's Recommendation Info:
http://www.wharton.upenn.edu/mba/admiss ... nts.cfm#a4
The Admissions Committee requires two recommendation letters, preferably from supervisors.

http://www.wharton.upenn.edu/mba/admiss ... ca.cfm#rec
Beyond your personal essays, the Admissions Committee would like to learn about you from two independent people who know you well. We prefer recommendations from people who can speak directly about your aptitude for, or accomplishments in, leadership and management. Thus, work-related recommendations are more valuable than academic ones.

Select the two people who really know you and your work, who you believe can best address the questions asked, not the two most important people you know. If a Wharton graduate happens to be one of those two people, he or she may be able to use his or her understanding of Wharton to describe how you will fit into the Wharton culture. Please don't seek out alumni who aren't truly qualified to write about you.

Recommendations should address the range of questions asked on our Recommendation Form and provide details, depth, and insight. Please make sure your recommenders understand that an effective recommendation is more than checking the right boxes and writing a couple of sentences. If the recommender believes that you are a good team player, he or she should present an example or two that illustrates that point. Useful recommendation letters are usually two to three pages long. You may want to brief your recommenders beforehand so they understand the competitive nature of the admissions process in which you are engaging.

Applicants working in family businesses, entrepreneurial environments, or other nontraditional environments will need to be more creative in terms of choosing recommenders (and perhaps use the optional essay to allow us to understand how you made your choices). You may consider clients, mentors, or those that you have worked with in the community.