I noticed microcontroller programming isn't so hard after all, and I want to raise the bar (as well as avoid having to buy AVR programming board). I'm going to buy myself one of those 12€ ARM chips and wire it up!

Before getting one I'd like to understand JTAG and serial port interfaces better.

Do I manage with USB->RS232 -cable? Where do I find a fine linux-visible cable with low price tag?

Is it good idea to do buy USB->RS232 (and then wire it up) or should I actually buy USB->JTAG cable?

Oh.. I found more info on this one. Serial port throws out and in only one bit at a time so I can't use it on JTAG.. well.. at least if I refrain from bridging the gap with a microcontroller.

I need a USB to parallel port instead.