Here's another good reason to have pulling spoke heads outside (copied this from Sheldon Brown's website): "If the chain should overshoot the inner sprocket due to the derailer being mis-adjusted or bent, it is likely to get more seriously jammed between the spokes and the freewheel if the spokes slant(*) so as to wedge the chain inward under load."
* built with pulling spoke heads inside.
Here's another tip: Never reuse unlaced spokes. It's fine to reuse spokes if they've been trouble-free, but keep them laced in pattern (I do this by taping each final crossing) when removing the old rim. The reason for this is that each spoke takes an individual "set" when first built into the wheel. If it was put in another position, It would take a new "set" and loose strength because of metal fatigue.
Also, I always cross the spokes over at the seam on 24, 32, 40 hole. I believe Jobst Brandt and Peter John White that this makes absolutely no difference, but customers might not, and does it really make it harder to get the pump in there? - NOT!
Dan Christopherson
Lopez Island, WA