Ok we all know 4th use as an indexer for rotary work on the mill but has anyone tried to use it (implement it) as a lathe attachment as well? Would that not be a cool idea to convert your mill into a lathe? It would have to go 1500+ RPM to be considered suitable!

It IS cool if I say so myself.
I has to be a special 4th axis (http://www.hossmachine.info/projects_5.html), a rotary table type won't do.
With their gear reductions, you would have to spin the handle
about 108,000 rpm to get 1500 at the chuck.
Hoss

Ok we all know 4th use as an indexer for rotary work on the mill but has anyone tried to use it (implement it) as a lathe attachment as well? Would that not be a cool idea to convert your mill into a lathe? It would have to go 1500+ RPM to be considered suitable!I know this guy
"Hoss" has done it. I believe he has a set up so he has a belt from it going to a stepper so he can use it as a 4th axis and then he can take the belt off the stepper and put it on a regular motor to use as a lathe. You'll have to look through his video's http://www.youtube.com/profile?user=hossmachine&view=videos