In Bartlesville, about a minute ago... lasted a good 15-20 seconds. Sounded like thunder, then thought it was something on the TV making my subwoofer go nuts... then noticed my speakers and TVs were shaking.
That was kinda freaky - mainly because it lasted so long. Kept waiting for it to stop, it kept going on and on. I couldn't judge how strong it was, but it was definitely notable. Made my gut feel weird. I am gonna guess a 3.5 or so. Maybe up to a 4?