Leghorns are very pretty, with large floppy combs like a film star's hair, over one eye. They're originally a Mediterranean breed, and the large comb is there to help them remain cool in hot conditions. In areas where the temperature goes well below freezing in winter, this may cause problems as the combs can get frostbitten - in a hard winter in N.Yorkshire you might need to treat them with Vaseline to help prevent this. They're very active and flighty, hard to catch and easily spooked. Mine like to have a high perch to fly up on, way above where the others hang out together during the day. Mine are both Leghorn hybrids, one is a White Star and Dinosaw recently said that White Stars are actually purebred leghorns under another name, quite small birds but they lay good-sized eggs. The other one is a much larger brown Leghorn hybrid, with the Leghorn appearance and temperament but with beautiful brown and gold feathers. The White Star lays bright white eggs and the brown one lays white eggs that don't look quite so white against the eggs from the White Star, sort of like a Persil advert! There are also Exchequer Leghorns, also known as Harlequin Leghorns, which have white and black patterning. This place in Nantwich has some Harlequins and also sells eggs. http://harlequinfarm.webs.com Nice pics on their Photo Gallery.
Some more pics here, but this place is in Devon and sells POL pullets. http://thepurebreedpoultry.co.uk/index.php?id_product=24&controller=product