Thanks so much guys! Though I had a bit of difficulty installing TIG's truetangents, once installed it solved my problem. The link to the thread was most enlightening. Fredoscale also looks to be another very useful plugin. Thanks again for the help, I really appreciate it.

Much like tilting a ladder against a wall, what I want to do is rotate a horizontal plane so that it is "leaning" against the face of a vertical plane.
The problem is that I cannot get the rotated plane to snap to the surface of the vertical plane.

The only other way I can think of doing this is by drawing a circle perpendicular to the axis of rotation with a radius the length of the the plane being rotated, then the point where the circle intersected the vertical plane would correspond to precise point of contact for the two planes. However because Skectchup's circles are really multi-sided polygons, as oppose to true circles, the point indicated by this method close but imprecise.

I fairly comfortable with Sketchup, and use the rotation tool quite a bit.
And this does seem to be a very simple problem.
Does anyone have an idea how I might solve it?

Thanks much for the help, that did the trick! I'm new to SP and greatly appreciate the assistance this forum provides.

I'm using SU ver 8 and SP 3.2 on vista. My construction is just 3 groups: a cylinder, a tube (with a flange foot); and a box (used as a base). The cylinder is inside the tube and the tube sits on the box. I group the piston with the cylinder and joint connected it to the tube. I set the piston/cylinder to "frozen". When I press play this allows me to reset the piston controller from 0.5 to 0 before activating the piston action by touching the model. (Which is what I want to do.)

However, the "frozen" setting for the piston/cylinder does not work if my construction has 2 (or more) joints i.e. when I start over and group a piston with the cylinder and group a ball joint with the tube, and then joint connect the the piston to the tube and the ball joint to the base. In this case the cylinder is always advanced to the 0.5 setting of the controller immediately upon pressing play leaving no possibility of initially resetting the piston action to 0 before activating the model.

Does anyone know of a way to fix this problem? My goal is to be able to set the piston controller to 0 as an initial setting before any action takes place.

Thanks in advance