One other caution regarding soldering, but more regarding de-soldering. For the ISP on the Baby-O, the holes the ISP fit into also act as vias to bring PB3 and PB5 out to the edge of the board. (Pretty sure this is true of most of the pins on the ISP, but I know it's true for those.) No sweat. Works great. But over the weekend I was helping a friend with their Baby-O and the ISP connector wound up installed upside-down. A little de-soldering and the ISP connector was installed the right way.
Problem was during de-soldering two of the pads got lifted, breaking their traces. One one of these it happened on the leg between the ISP and the edge of the board. On the other it happened between the ATMega and the ISP. Two wire jumpers fixed it, but I'd rather not go through that again if I can avoid it.
Be as careful (or more so!) de-soldering as when you're soldering!