Okay, so all you have to do when your microwave gets nasty (I wish I had a BEFORE pic so badly) is take a wet sponge and lay it in the microwave (I take out the round tray first and wash it in the sink) for 30 seconds.
Open the microwave and carefully take out the sponge and you have a steam-cleaned microwave that only needs a dry towel to swipe out the gunk and you are done.
I wish I had tried this long ago ... it makes cleaning the microwave fast and kinda fun and it's something the kids can even do for you. And I am all about having the kids do things so (1) they can learn life skills (2) they can feel helpful (3) you can take a dang break every now and then to do something cool like write on your blog or read a page of a book for a change.
Here's the book I'm working on to go with the blog!