When you ride the tube (The Underground) by standing in the aisle and and balancing without holding on for the purpose of fun and laughs and enhancing your skills.
Ai! It was a brilliant ride (Tube surfing) today! I picked up at Hammersmith and for an extra challenge rode eyes closed listening to The Futureheads on my iPod.

by Karen E September 9, 2008
to balance (hands-free) while riding the subway in London, which is called the tube (hence, tube surfing)
"Right mate, we were kicked off the bloody tube for tube surfing"
by bonster2000 March 27, 2007
The act of clicking on random videos on youtube, and in the end landing on a really random vid.
(Guy 1) Dude, I found a video of a cat eating a dude's shit.

(Guy 2) What? Why did you look that up?

(Guy 1) I didn't, I was just You-Tube Surfing and it came up!
by Macca97 February 20, 2011