Thanks for all of the replies. He doesn't wear shoes in the house, so that excuse is out. He was pointing to his ear today so maybe I'll have them check that out, he's due to see the doctor anyway. He's been walking since 10 months old, and he runs, kicks balls, and jumps (with one leg

) well. Everytime I turn around he gets bigger, so maybe it is that he's adjusting his center of gravity and spatial reasoning.
Well, if he's been pointing to his ear, I'd definitely get it checked out!
When my daughter was 22 months old, she started telling us, "Bumpy ear!" I asked her which ear? Sometimes she'd point to one, and sometimes the other. I didn't know what she meant, but she had a little bit of a cold, so I thought she might be stuffed up. This went on for a little over a week, and I couldn't decide whether she was sick or not. Most of the time she was playing normally and she seemed fine. Maybe a little sniffly, but nothing much.
Then on Christmas Eve she started running a fever, and crying non-stop. She wouldn't quit even though she was exhausted, and I got worried enough to ask my husband to take her into Emergency. His brother decided to go with him, since I had to stay home with the baby. On the way there, my daughter suddenly got quiet. Like, all of a sudden - she just switched off. When my husband took her out of the car seat, she was awake but looking really kind of stunned - and one of her ears was bleeding.
Of course they rushed her into Emergency, but they were two scruffy, unshaven guys with a little girl. So they got shown into a little room where various nurses kept asking them when they'd dropped her on her head, while other nurses called around to other hospitals to try to figure out if she'd ever been admitted anywhere else (child abusers tend not to use the same hospital twice). Finally a doctor showed up, looked in my daughter's ear, and said, "My! That's quite the raging ear infection you've got there."
It seems her eardrum had burst on the drive to the hospital, and that's why she was bleeding. She'd stopped crying because of course the moment it popped she wasn't in any pain anymore.
He wrote a prescription for antibiotics, instructed them to buy Auralgan (a topical anesthetic for ears), and sent them home. My daughter's other eardrum burst on the way home, so my husband brought back a happy, exhausted kid, bleeding from both ears. I felt SO guilty for not understand what she meant when she'd told me she had a "bumpy ear"! And I always paid close attention to any possible signs of ear infection after that.