re: Somebody explain the practical differences between the various business majors.

Finance or Accounting. CFA (finance) is a whole lot harder to get than a CPA license, but you can major in finance and as long as you take the correct electives, be eligible to sit for the CPA

marketing is a waste
general business may as well be general studies
econ is hit or miss, id recommend staying away
the whole ISDS/computer informations is on the upswing, very good payoff after graduationg

cliffnotes: acct/finance or ISDS