M is 10. M does not play by himself. If he isn't allowed outside the answer is to pester me into oblivion. I spent all morning playing and then watching some silly monster movie on syfy. Now, I want to do my nails and it's "mom, what do you want to do with me? Mom, what can I do? Mom, let's just leave now. Mom, I've decided I want to go to the diner. Mom, mom, mom, mom, mom...."
GO PLAY BY YOURSELF! You are 10 years old! You've been an only child for 10 bloody years and you can't play by yourself?!?
Anyone have any ideas on how to get this kid to play alone?

This isn't really advice, but here goes anyways...
I've had trouble with this too. Kids want constant stimulation, but boredom breeds creativity. Your question (something I struggle with too) reminds me of this article: http://online.wsj.com/article/SB10001424052748704271804575405511702112290.html
I don't agree with 100% of what the writer says/implies by any means, but I do think he makes a good point. In my house, I try for less screen time and more alone time. Part of it is just habit and practice. I have a few activities that I have listed for the kiddo to do on his own (everything from this book: http://www.amazon.com/642-Things-Draw-UNNAMED-ANONYMOUS/dp/0811876446, to toys, to chores). Also a household ban on the phrases "I'm bored!" and "there's nothing to do." He's a little younger than yours, though, so ymmv.
Yeah, I see what he's saying, but that's not my issue. Even during the school year (which this year meant absolutely no television or video games, he only recently regained those privledges) I was having the same problem, and he still wasn't reading.
Today I bought a family-size inflatable pool. He doesn't expect me to get in it, he doesn't expect me to be outside the whole time. I've opened the door so I can hear him, and he's been playing by himself, then with friends, now by himself again. He's got his zoob building set and he's making sea monsters. I am having a great afternoon.
If only we could do this year round...