AVR-Chat

I'm sticking one of these on a board, for my sins.

Do I gather it has a 1-wire programming mode, which COULD use a 2-pin 
connector, but that you can only use the 2-wire mode once you've blown a 
fuse which requires a 6-pin ( or 10-pin ) mode?

So if I put on a 6/10-pin pseudo-connector, and drive it once through 
pogo-sticks or something, then thereafter I can just use a 2-pin 
connector?

Would I ever want/need to un-blow the fuse and use the 6-pin version 
again?

David