11. Microsoft Smart Display (2002-2003)

The Wikipedia entry says it all: "Smart Display was announced in early 2002, released in early 2003, and canceled in December 2003, having never achieved more than negligible market penetration." For those who don't remember exactly what Smart Display (codename Mira) was, the concept was a wireless monitor that detached from its base and turned into a tablet PC (that was unfortunately tethered back to your desktop computer). It was sluggish and buggy, and was hurt by the slower 802.11b Wi-Fi connection of those years.