I have an Arduino Mega ADK. I was planning on loading sketches to ATMega328s using ArduinoISP. Using http://arduino.cc/en/Tutorial/ArduinoToBreadboard I can burn the bootloader with it, but it says to upload sketches to remove the microcontroller from the Arduino... obviously, that would be a little hard to do with a Mega, and especially when putting it back... can this step be ignored when using the Mega or do I have to use an Uno?
Just buy the FTDI cable or small adapter board. It makes life much easier and will save you time in the long run.