for some reason that reminds me of a festival here in the states called the burning man, if i recall correctly, where people gather and burn a giant effigy (though i'm not sure what it represents). i want to say they do it out in arizona. it seems like a very odd thing to do today, though i don't think it's got any particular meaning for most of the people who see it as a party (though certainly there are those who see some deep religious meaning in it).
another 'holiday' happens in sturgiss, a biker festival (n. dakota? damnit, i used to know these things), where bikers from all around the country congregate and have a good time. a newer version happens in myrtle beach, s. carolina, called 'black bike week,' which is sturgiss' equivalent, the difference there being they trash myrtle beach and plenty of businesses go on 'haitus' for a week.
of course, there's spring break, where mostly kids/college types go to daytona (college, mostly), another city in florida where the teeny-boppers go (can't remember the name off-hand), or cancun (these are where most of spring break happens, but not exclusively).
of course, every year we have state fairs, county fair, and city festivals. my hometown has 'the paper festival.' whee. around here there are pretzel, strawberry, apple, and sauerkraut festivals. i've been to the tobacco festival a few times, too, but that's near kentucky.
the point is that once you stop to think about it, we humans celebrate anything. often it's a great excuse to get drunk. let's face it, if we 'celebrate' pretzels, we'll celebrate anything.