DJ,  Its fairly unusual but I have had a provider do that...they will typically place your penis either flat against your stomach or pointed down toward your feet and slide back and forth on it.  If done right it feels great...and its been done to me uncovered since there is no penetration.

And, it is done privates to privates, usually without protection. There's been great debate on the General Board regarding how safe it is to do, even though there's no penetration.

Re: the name

OK all, it's the "camel toe slide" (my unofficial take).

It's a camel toe, and you slide it... Hence the name camel toe slide

see links for camel toe:
http://ratemycameltoe.com/vote.php
http://www.cameltoe-world.com/
http://en.wikipedia.org/wiki/Cameltoe