Orange has unveiled a viral web game that uses a GPS tracking device attached to a bull in a field somewhere near Somerset.
Spot The Bull exploits the mobile network's sponsorship of the Glastonbury festival, offering prizes to players if they can correctly predict the location of the creature.
The GPS gadget, which is fixed on to the bull, relays its location to a Flash applet at www.spotthebull.co.uk, along with four near-live webcam images from each of the field's corners.
Users must guess the grid quadrant in which the bull will be standing every day at 3pm to win Glastonbury tickets.
While such locative media has frequently been used in art projects, it has rarely been deployed in marketing scenarios.
"In the gaming arena there's lots of stuff - treasure hunts, man hunts, all kinds of hunting," Iain Tait, founder of the Poke digital agency behind the launch for Orange, told E-consultancy.
"I think this is the first GPS-enabled livestock, though.
"I think there's all kinds of applications of this sort of technology. We take a reading every few minutes and then convert the GPS data into co-ordinates on our map.
"Of course, with GPS, there's a margin of error of a couple of metres. But we've done everything we can to minimise the degree of error so that the contest is completely fair."
Tait said Orange was due to launch further technological developments at the music festival.