With me, especially if in any way hungover, I can quite happily spend about 75% of my waking dayjust googling things and clicking through links on Wikipedia aimlessly, lazily researching whatever pops into my head. The chain will go something like

Crispin Glover > Tallest bridges in the world > The Matterhorn > Antarctica and arctic > extinct fish species > Dropping the little streetview man into different parts of Tokyo and Mexico > Old maps of London > Where Oprah Winfrey's from > How old is Roger Ebert > JFK > Jack Ruby's Nightclubs > Platinum Mining > The circle of fifths > Deicide > etc etc etc.

It just seems to go on and on and on, with breaks for water and biscuits and then it's dark outside.