I like to attend festivals and events. However, festivals and events are not my main reasons to go somewhere. But, they are for many other people. I'll have to admit that there are some really great festivals and events in the world. If you have a particular interest, you should be aware of some of them already. Please not that some of the web sites listed here are so much more than just a listing of festivals.
Wikipedia: Festivals has a listing of hundreds of festivals by that are organized by continent, country and topic.
2camels has a strange name. I'm not sure why they call it 2camels, but it is a very good web site about festivals and events. If I were short on time, I would make this one of my first stops if I were lookinjg for a festival or event. If I wasn't short on time, it's a great place to wander around.
Rough Guides has a listing of of festivals by that are organized by month, country and theme. There is a Top Ten list that is... well... interesting.
Bugbog is so much more than just a web site that has good festival listings. If you haven't been to Bugbog, you should go if for no other reason than the festivals page. Great pictures.
World Reviewer Festivals is a subset of the World Reviewer web site and is so much more than just a listing of festivals. The World Reviewer web site is a listing of the world.
happywink is a web site dedicated to festivals. It omits a couple of the ones I've gone to, but it's a very good web site for finding events and happenings.
World's Wackiest Festivals is a page at the Oddee web site. Oddee is a web site about the the odd, strange and bizarre. It's a lot of fun. The vestivals listed on the page are what the web site espouses to be the 10 weirdest festivals in the world.
Festvialpig has what I consider to be one of the best looking pigs on the Internet. I'm smitten with it. I think the pig is cute and the web site is worthy of a visit.
Whatsonwhen is what it says it is. A person has to ask themselves how many festival web sites there are and, in the end, wonder if it's worth visiting another one. Well, I'm not sure. But, if a web has good search capabilites (and this one does), it may be worth a minute of your time to search for that one special event in that one special location at that one special time.
World Festival Network is one big web page. Imagine trying to put a list of every festival in the world on one web page. It takes a while to load.