Here's a great way to send someone a drawing, although it is a bit complicated. But compatibility is all but guaranteed.
This requires Adobe Acrobat Pro, FYI, something that a lot of folks have around, and Meshlab, which is Open Source.
Make a blank document and save it to PDF. I typically make mine 16:10, as that's the aspect ratio that I'm working at (so I make a custom 16"x10" doc, no margins, in Word). Open that in Acrobat Pro.
Go to SketchUp, select the parts of the model that you want to send (or the entire thing), and export as OBJ. I use the following options:
Export only current selection
Triangulate all faces
Export two-side faces
Swap YZ coordinates (Y is up)
Choose Tools>Multimedia>3D Tool. You'll get a crosshair cursor.
Make your view port with this. I typically fill the entire screen.
Acrobat will pop up a file requester dialog. Enter the .U3D file path there. Select Advanced Options. Enter the following options:
Launch Settings: Enable When: The page content is opened.
3D: Background color: White
3D: Lighting Scheme: White Lights
3D: Rending Style: Solid (try playing with the other settings for your purposes)
3D: Show toolbar: (checked)
See attachment. It works in any recent Adobe Acrobat reader.