any advanced technological device, usually pointless and/or confusing. similaly: gadget, widget, whatchumacallit, etc.
palm pilots, global positioning systems, radar detectors, digital camera widgets, generally anything small and electronic.
Much like the gremlin Gizmo, only in human form. A spoiled child. The child is cute and cuddly until you piss them off by telling them the dreaded word "No" then they turn into a hideous little monster.
Derogatory term used to describe someone of Japanese descent. Derived from the fact that these people are always gizmo-ing about and making crazy devices to do all sorts ofperverse things that only the Japanese could think of.
Try calling your Japanese friend a gizmo, and you'll see just how right it feels.