So I'm riding home with a co-worker this evening, and we're keeping a fairly decent pace around 20mph. Shortly after we fell into our groove, I notice a guy sprinting up behind us. He took rear spot on the line for about a mile, and I just assumed he was taking a breather before his next sprint when he flagged out and passed us both... but then he slowed and dropped back in and said he'd take a pull for a while.
He picked up the pace to around 23mph after stating "you guys were doing about 22 when I was chasing you down" and we hung with him at that pace for the next mile or mile and a half. He dropped to the back again and I kept the pace as long as I could without totally blowing up.
After we reached a clear straightaway, he thanked us for the pull and took off at what must have been 27mph and didn't even look like he was putting any effort into it. I dropped pace back to 19 - 20mph with my co-worker to finish out the last few miles together.