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YouTube has multi-video uploading. This comes in the form as downloadable software that you can get here. Once you've added the multi-upload software to your computer, you'll be able to access the Multifile Upload Page.
This is where the fun begins. Well, if you call fun waiting for several video files to upload. Each video can take up to 10 minutes in length, and up to 1GB in size. The wait time is compounded, since you'll be adding several files, but it's all worth it in the end, right? The uploaded videos of course go to your My Videos page once they've been processed.