Little Snoop is a small installable application that runs on your computer and makes Snoopon.me possible. Little Snoop is an open source software. You can find its source code here.
Screenshot is a mini-snapshot of your computer screen or screens. Screenshot is maximum 320px wide.
Snoopee is someone you snoop on. You see live screenshot updates of your snoopees when you sign in to Snoopon.me. 'Unsnoop' links lets you remove people from your list of snoopees.
Snooper is the opposite of snoopee, someone who snoops. Most of the time you will be both snoopee and snooper.
Screen trail is the time ordered list of all screenshots kept by Snoopon.me for a given user. The length of a screen trail is configurable to 48, 96 or 192 (unpinned) screenshots. When a new screenshot arrives to the full screen trail an older screenshot is removed at random.
Pin down (a screenshot) is to mark a snapshot as interesting to prevent it from being overwritten by incoming screenshots. You can find all screenshots you pinned down in your 'pinboard'.
Pinboard is a collection of screenshots you have pinned down to comment on them, share with friends etc. If the owner of the screenshot decides to delete it, the screenshot is removed from you pinboard automatically.