how to test a used lens?

I'm hoping to pick up a used lens next week and will most likely have several to choose from. When deciding to get a used lens that you can view in person, how do you guys go about evaluation and testing?

I already plan on bringing my camera and a charged battery. I plan on inspecting the outside for damage and wear as well as the glass for signs of damage. Beyond that i would also expect to make sure the AF works properly and that the zoom works smoothly.

Would it be a good idea to snap pics at certain incriments of the zoom range? How many times? Is there anything I can tell by doing that, if I only have a 3" LCD to view the photo on?

I'm sure I'm missing a lot here...

bring a flashlight, check for fungus/insects inside. if you've got several of the same one to choose from, listen to them as they zoom, note any grinding noises. Try them out on the camera, take your time.

If you have a laptop computer, bring it so you can download the sample images to view them.