I mean, humorous they may be, but there's no such thing as a useless item. It applies as much to players as the GM. Here's a basic overview of how those went on my sessions:
The Lute of Invisibility is a perfect utility for bards of all levels to help use their songs during combat. Also, as I quickly found out, dramatic entrances. ooli
The Wig of Persecution was a plot item, evidence in a murder mystery where the court adviser was found dead wearing it.
My players used the Axe of Grindness as a distraction when they were captured by a bunch of bandits. They argued that it's damn hard to sharpen an axe in the forest and it should give our rogues enough time to 'take 20' while their guard was preoccupied.
Aside from being a 1/day fireball, The Book of Canon is basically a low-level bardic knowledge substitute that anyone literate can use. I dropped many a hint to my players with it.