What about putting the ICSP pins as pads along one edge, three pads on one side and three pads on the other side. Then you can use a regular 2x3 header and shove it onto the edge, program, and remove. No soldering needed. Someone wrote a piece on that:
This is another option, although it requires you to make a custom header:
http://www.daniel-spilker.com/blog/2011/04/25/isptouch-for-avr-microcontrollers/