These are some of the things I've been looking at and want to buy at
some point in time.
[Olimex USB JTAG](https://www.sparkfun.com/products/7834) to debug the many devices I have with JTAG. Ordered it in January, 2007! [RS232 Shifter](https://www.sparkfun.com/products/449) to shift from TTL to RS232 signaling. Made it.