From ParentHacks:

Instead of buying foam protectors for your table corners, cut slices in old tennis balls and wedge them on. This works great on our kitchen table which is exactly at eye level for our new walker. As an appealing bonus, it looks like pac man is eating our table.

….using duct tape (the home hacker’s faithful companion) to affix tennis balls to the edges of a kitchen island that’s just my son’s height, which saved my son a few good knocks on the head while he was there!

It’s a unique idea, but really, what baby isn’t going to go right for them, undo the tape, and stick their finger inside it, get it stuck, etc?? Lil’ Duck learned how to undo duct tape when he started crawling, somewhere around 7 months….. so I figure the life of this idea is VERY small unless your little one despises tennis balls….. the pac-man reference did make me laugh though, so that is something.