Don't kno anything about this personally but a quick google resulted in this:
"Let's start with a quick overview of what are commonly known in the money management biz as "wrap" fees. About 20 years ago, wrap fees or wrap accounts were a new way for individual investors to pay a money manager to choose and then monitor a portfolio of stocks or bonds or a combination of both."
More here:
http://money.cnn.com/2005/08/02/pf/expert/ask_expert/