Thanks for the responses, guys.
I had new brakes put on and the front wheel bearings repacked, it seems to be happening much less often, and with much less force when it does, and it doesn't last as long.
It started doing it early yesterday, and it stopped immediately when I took my foot off the gas. Did this twice to confirm. It's more likely to do it after a left turn or going around a curve to the left. But later, it just did it out of the blue, even with my foot off the gas. Weird.
Sounds like it's time to get in and start checking the other front end components.