Let's Crate is a free file sharing service that is very easy to use. You can simply drag and drop files to a crate and share the url with someone so that they can retrieve the files. If you don't create a free account, your crate is available for 30 minutes. If you take 2 minutes and create a free account, you can have the crate forever.

It is very easy to use and the only downside I have found so far is that the crates can not handle very large (over 20 MB) yet.

This is a great way to share files with students or parents or other teachers. If it is going to be a quick thing, you don't even need an account.