ShareByLink is an easy-to-use open source file sharing service and tool.
The package is all about simplicity. There's no registration, no account to create: just install the program, then right-click a file and select "Share file(s) online..."
Whatever you've selected is then uploaded to a central server. This is given a link, which is displayed, but also copied to your clipboard. Pass it on to someone else and they'll be able to download the file.
The link expires after 30 days, but you have no further control over that, or the file. There's no list of files you've updated, no web interface or log to view them (because you don't have an account), and no way to delete the file early.
We also found no information about the maximum file size you can share, although uploading a 1GB video appeared to work.
ShareByLink is very easy to use, but it's distinctly short on documentation, and provides no control over your files once they've been uploaded. Try it, but not to share anything sensitive or confidential.