The new Philips LPC210x ARM microcontrollers look very interesting, so
I'm working on a very simple low-cost prototyping system for them.
Details are here: http://www.geocities.com/leon_heller/lpc2104.html
Apart from the device being in a 0.5 mm pitch LQFP48 package, it is very
easy to use and requires minimal support circuitry.
