The Raspberry Pi is so accessible and affordable, and that means it can be easy to start a collection, even unintentionally. There are now nine different boards available, and amazingly all of them are still useful for something. Being so low-powered and easy to maintain, they have a surprisingly long shelf life, and a continual ability to keep working on whatever set of tasks it[he]#039[/he]s been set up to do.

Source: LXer – How many Raspberry Pis do you own?