Oh yeah. I had one jump twice while I was in the room. Some weird flap, flap sound got my attention. Back into the tank he went, cat hair and dustballs included. He did just fine until he jumped out again the next week. That time the cats found him before I did.
Why they feel that there must be a better life on the other side is beyond me.
I was walking in front of my open top 125 one time and something flew out of the tank and smacked me in the chest mid stride. Guess what it was? He was lucky I was walking by or the cats would have had a fishstick later.