Not sure if this has been posted here before but it is damn useful so if you didn't know here you go.
The function "/script RetrieveCorpse()" is what the accept button on a corpse run does, but this function does not check the z-axis and therefore allows you to corpse rez even if your corpse is under the map and too far away to pop up the message.
Simply run back to your tombstone and use this script, and viola no more having to sit for 15 minutes with rez sickness.
Also, just fyi, "/script RepopMe()" is how you release if you die from falling under the map.