I've got a scar on my chin from making that very mistake. I forgot to check the front QR on my mountain bike.

I pulled up on the front wheel to go over a train track. My front end came up just fine. However, since my wheel was no longer attached to my forks and hadn't received the news, it kept going forward. My fork blades hit the pavement, followed shortly thereafter by my chin.

If memory serves, it required 6 stitches to close up the gash.

To make things better, this would end up being the first of two incidents in a 48 hour period that required stitches.