Before you ask, I did a search, but something seems wrong with right now.

Are there any tutorials which include a little c/c++ code that shows how one can manipulate the GPIO and i2c bus on the GumStix Connex board? Also, any tutorial on how one can update system drivers, programs, linux kernel, and the ethernet device's MAC address from within linux itself. Any links would be helpful.

Also, would manipulating a couple of GPIO lines be suitable for pushing data into a serial-in, parallel-out register? Is there a better way that someone could suggest?
Are there any lines on the gumstix which assert a power-on reset? Any simple circuits that assert a power-on reset aside from any on the gumstix that you guys can suggest.