Any interesting electronic projects using the entrails of
a microwave oven?
They aren't really a source of parts. They are fairly simple devices,
with much of their size used up in the cooking space. And what parts are
there are likely to be pretty specific, to microwave or to high voltage.
The only way you'll get much in the way of useful parts is if you are
doing something with either of those things.
VCRs are a much better source of common parts. Lots of resistors, and
capacitors. Plenty of small signal transistors. Some neat radio related
components, if that interests you. Usually some common DC motors. All the
screws you can use. They are also easier to carry home when you find them,
compared to microwave ovens.
Michael