well, any dangerwank
but with higher levels of danger. Wanking whilst presenting newsnight. Wanking during a conference call. Wanking during sunday lunch with the vicar. That kind of thing.
( the mighty badger Aphrodite, on a bar stool, by your side, Thu 11 Mar 2010, 14:39, archived)

Wanking during sunday lunch with the vicar.
That's not a danger wank, that's practically expected.
( The Teviot Moose major 5th., Thu 11 Mar 2010, 14:40, archived)

Maybe with YOUR vicar.

( the mighty badger Aphrodite, on a bar stool, by your side, Thu 11 Mar 2010, 14:41, archived)

what about wanking while walking a tightrope over a crocodile pit?

( RR I love you ... in a way, Thu 11 Mar 2010, 14:46, archived)

Hmmm.
Certainly in the ballpark. I think, strictly, the activity itself needs to be fairly risk-free, such that the danger comes solely from the masturbatory element. But it's not an exact science, of course.
( the mighty badger Aphrodite, on a bar stool, by your side, Thu 11 Mar 2010, 14:48, archived)

OK
What about a businessman twist on the old 'shouting downstairs to your mum' one?

Pressing the stewardess call button on a business class flight and trying to time it just right so that you can clean up with the hot towel.
( RR I love you ... in a way, Thu 11 Mar 2010, 14:52, archived)

hahaha. cunt.
it's a good job i'd already finished my tea or it would be new laptop time.
( the mighty badger Aphrodite, on a bar stool, by your side, Thu 11 Mar 2010, 14:56, archived)

How about wanking when on a random picture website?
"Tits....tits....arse....tits....tits....SPLATTERED CAT!...tits..."
( Theoban What of it, Thu 11 Mar 2010, 14:51, archived)

This, I believe, is the classic "random shuffle" dangerwank

( the mighty badger Aphrodite, on a bar stool, by your side, Thu 11 Mar 2010, 14:56, archived)