The ECE department has purchase 10 USB logic analyzers (Intronix LA1034 LogicPort) for use by Senior design teams. These can be checked out from Dr. Reese. These are trivial to set up and use:
If you are having I2C or SPI port problems, this can be invaluable in determining what is doing on with your system. Or, if you are trying to track to multiple digital signals, then you need this instead of a scope.