A quid is a slang term for the British pound. So currently, 1000 quid (or 1000 pounds) is about $1500 US dollars.
Sidebar is a theme feature introduced with Version 2.2. It's basically a vertical column provided by a theme for displaying information other than the main content of the web page. Themes usually provide at least one sidebar at the left or right of the content.
Sidebar gadgets - run on the desktop or be docked onto, run on the Windows Sidebar. SideShow gadgets - run on auxiliary external displays, such as on the outside of a laptop or even on an LCD panel in a keyboard, and potentially mobile phones and other devices.