All I can say about the Kamakura festival is if you are in the area at the right time it is a great bit of "culture" to see. Lots of fun, and many strange people. It reminded me of a con, after the kids have left for the night (though I have definitly seen stranger costumes at cons). The big event was the parade of mikoshi (portable shrines) through the streets of the town near the shrine, there were three mikoshi. The main one, a flourescent pink thing that looked like nothing more than the worlds largest dildo, was carred by a team of drag queens, more than slightly sloshed. Following them were two more traditional looking mikoshi, in that they were semi-enclosed, both with representations of the "Iron phallus". THe legend is that a local princess really wanted to be married but every proto-husband came away from the marriage bed a few inches shorter as a result of the literal vagina dentata that she posessed. Eventually a blacksmith made himself an iron version which broke off all the teath and they lived happily ever after, etc... Anyway, that's what this festival is based on, it's a fertility festival in the true shinto tradition. This also means that they try to sell you loads of things that are even remotely related to sex, fertility or the "iron phallus" (there are even charms! o_O ). The most popular omiyage are lollypop candys in both male and female shapes (the male are far more common and popular), just about everyone on the shrine grounds was eating one of these things without a care.
The only bad thing about the festival is that it's a forigner magnet. This wouldn't be so bad except it's near one of the US bases......that always makes things more complicated and not as much fun. ~_~
...........I'd post pictures but I don't think my hosting service will let me upload them, sorry.