Microwave friendly utensils, what qualifies as

Here is a set of guidelines I found from a major manufacturer: http://www.geappliances.com/search/fast/infobase/10001216.htm

As you mention, any metal items or items with embedded metal are not appropriate. Thinner and bendable plastics are probably not a great idea either since they can melt. Most ceramics and glass should be okay.

When in doubt, check to see whether the item is labelled as microwave-safe, and if you can't tell, test it first using the method described in the linked guidelines.

Since the GE link has by now gone dead:

No, not all ceramic items can deal with it well. Some glazes or decorations on ceramics contain significant metal, and some ceramics will soak up a lot of moisture over time. In both cases, using them in a microwave can lead to bad heating, surprisingly hot containers, or even damaged containers.