While we were in Scotland we saw jellyfish on two occasions. The jellyfish above was on the beach at Durness (24 June 2013).
The one below was at Chanonry Point (26 June 2013). It was part of a cluster of stranded jellyfish: in the evening light, we counted 56.
Both photos (I believe) show the Moon Jellyfish, also known as Aurelia.
I shall record these sightings on the Marine Conservation Society site. Jellyfish are linked to Leatherback turtles in the food chain. These magnificent, but threatened, turtles make huge underwater journeys in search of these strange sea creatures.
The stings from some species of jellyfish can be dangerous, so it is important to treat these free-swimming marine animals with care.
Postscript ... 5 August 2013: you may be interested in this BBC report.