Plop your bootloaded part on a breadboard with 16MHx xtal, two 22pf caps, 10K reset pullup resistor.Get an FTDI Basic (or equivalent), wire up the Atmega Vcc, Gnd, Rx, Tx, and Reset to the FTDI Vcc, Gnd, Tx, Rx and DTR pins.Tell the IDE you have a 16 MHz 5V Duemilanova, should be ready to go!I think there are playground examples that discuss just this.There are other options as well - such as using the FTDI on your existing Arduino to do the same (if so equipped).
I would go with this instead.http://yhst-27389313707334.stores.yahoo.net/arliandpropr.htmlThere have seen some quite recent posts here saying the right angle one is having trouble with traces breaking.This one is good & solid. I have been using mine to program prominis since August with no problems at all under Windows Vista, and I have plugged & unplugged it a lot!I think I may have missed something when I was setting up the drivers, that was a bit of a struggle the first day or two. No problems since.Where you are connecting to a breadboard, you may want to scrounge up a set of 0.025" square posts that you plug in the board, then plug this onto the pins and make your connections from there.
Why not make it foolproof? Put in a MAX1811 & LiPO battery, have them connect to a USB port for charging.Your way sounds less expensive tho. Diode wouldn't hurt.