Hi Ken. I share your enthusiasm for Sketchup. I'm especially looking forward to the day that I can send a sketchup model (with all the joinery) to my engineer for review, as it completely specifies everything I plan to do.

Try this trick: Map a shortcut key to toggle x-ray mode:

From the main menu, choose window | preferences.
In the list on the left, choose Shortcuts.
In the list on the right, scroll down and choose View/Face Style/X-ray.
Then click in the Add Shortcut box, and type a shortcut key or combo (I use Alt-X). Then hit the + button to add the shortcut. Then hit OK.
Alt-X (or whatever key you chose) will now instantly toggle x-ray mode. CB.