Question about latest mpguino setup

[rs3275]

Was looking through the opengauge source folder and saw the new mpguino diagram (v1.3). It uses the atmega328 chip, but has a few extra connections

A1
A2
RX
TX
PB2
PB3
AR

These were not on the previous diagram so I was trying to figure them out. I did some looking through the forums to find info on this new diagram.

I was able to find this page

hxxp://ecomodder.com/forum/showthread.php/differences-between-prebuilt-mpguino-code-official-code-14751.html

In which a member states there is no arduino dependency.
So I'm assuming that chip can just be programmed outside circuit and put back in, hook up vss-injector-battery-ground and you are good to go? Or is it a bit more complicated?

[dcb]

I program them with ISP, technically they do not need programming outside, but I hate explaining programming, but yes it is completely doable thousands upon thousands of people have figured out how to program these chips. Yes it can be a little complicated, but all those pins were pulled out specifically for experimentation by the adventurous.

[rs3275]

Got it, so this is just like the ISP circuits used in programming PIC chips, super useful. Not asking for programming tutorial, I know it's like the fish and fishing pole story.

So before I even get started I still need some sort of programmer to get the code on there. So I will need something like

USBtinyISP
USBtinyISP - Inexpensive USB AVR Programmer

or even simple parallel programmer?
Arduino - ParallelProgrammer

So just out of curiosity, what would be an example of what you could do with those extra pins?