Lie

I thought you lie in bed. Not on it.
Guess I was wrong. But I'm pretty darn positive that's how I've heard it from native speakers.

"Biggs, who used the screen name "CandyJunkie" on the bodybuilding Web site, started blogging about plans to kill himself 12 hours before he was found lying dead on his bed"

The general rule is this:

You lie *in* bed when you've got the bed covers pulled up on top of you.

You lie *on* the bed when you are atop the bed covers.

Of course, on a warm night, I could be sleeping on my bed, atop the bed covers, but still be "in bed"...

If someone calls you on the phone and ask what you're doing, you would typically say "I'm in bed" or "lying in bed." If it's the middle of the afternoon, however, and you're fully dressed, just relaxing, you would answer "lying on my bed." They both work depending on what the context is. JTT got it right.

Another comment: one can lie in bed. More rarely, one lies in THE bed. One never lies on bed, only on THE bed or on YOUR bed or on A bed, etc.