If you fly DL and keep a SkyMiles number in your PNR, that's an easy way to check.

When MissBumpMe! and I used to fly DL, we'd log into the other's account to see if activity had posted. If it posted, she was on her way. If not, she probably got bumped... again!

It's too bad CO's OnePass system isn't as instant as the DL system.