Is there a standard In Circuit programming connector for LPC chips?
I use Sparkfun's USB to UART board. I bring out UART0, reset and isp to headers. I connect reset and isp to ground with jumpers, then use FlashMagic. This only seems to work right if I also power the device from USB, so the grounds are common.

Sparkfun's board:

https://www.sparkfun.com/products/718