Some go for the Lulz, but also there are sites for LAFS (Least Authority File System). Here are two interactive ones based on the Tahoe-LAFS

• Tahoe Storage Illustration is a simple javascript page; it lets you enter data, pseudo-encrypt it, distribute it, and then wipe out cells of it to see how data could survive a failure.
• Tahoe-LAFS Storage Grid is a real instance where you can test the UI.

Neither demonstration addresses the giant elephant of storing data with a provider — managing authorisation and authentication — but the latter site comes with warnings.

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