You can share files through plenty of sites, so a new one needs a twist to make it compelling. Cloudup's point of difference: you can send a link to your files before they finish uploading, and you can create collections from local uploads and online sources.
To upload, you simply drag files onto Cloudup's interface and you get a URL for sharing. You don't have to do much else. You can add single files, but adding multiple files will create a collection. This makes for a great way to share photos, videos, and other related media. If you have files from existing online sources, you can just add them via URL rather than re-uploading them.
Cloudup recognises several URL types, such as YouTube videos, so you can have them in collections just like an uploaded file. Regardless of the source, you can send out a link before the files finish uploading. Obviously your recipients can't view anything until everything goes up, but you at least don't have to wait around until Cloudup finishes to get the URL.
Cloudup currently exists as a private beta, but they've provided us with 2500 invites so Lifehacker readers can give it a try. If you want to sign up, use the link below, otherwise you'll end up on the waiting list.