I tried IDC pins, but they are too thick for insertion into IC sockets. I tried some machine pins also, but the ones I tried have shoulders machined into them and hold the board too high off the original. There are also some with molded ends that slide over the PCB, which after soldering, you can then bend the pins to right angles, but then the pin width across the board moves out to 0.4" or more, so not suitable.
The pins must be around, I've seen pre-assembled boards on the web that have them, I just haven't been able to find similar.
cheers
Tony