Fimmvörðuháls
Fimmvörðuháls ("5 Cairn Pass") is one of the most popular hiking routes in Iceland. There's a long-standing tradition to do this hike overnight at summer solstice - I've participated since 1996. In addition I've led a number of groups across the pass, both with and without overnight stops at the top, where Útivist operates an excellent lodge.
Having done this hike so often I've got more pictures than you can shake a stick at - the ones pointed to by the title were taken in 2006, there's a bunch from last June (2007) at http://leifur.smugmug.com/gallery/3072242