I'm on the verge of going this route.@iaresee we cheat nowadays and use SetListMaker on iPads that scroll lyrics and chords and other cues... the sad part is... we need it even for original material we've played for over two decades... lol... part of getting old.
Oh! Phish has prompters! At least Trey has one for lyrics and some of the changes. Once I found that out I became way too aware of Trey looking down while singing. They became a staple on tour around 2010 IIRC.
Pics here: http://forum.phish.net/forum/show/1375094386