Symphony.

Is there such an extension as a hashed valued reflection field?

Maybe not worth an extension as such... wondered whether extending the hash field to store values of another field rather than it's own as an option when building the Section?

I would like a field like this, as I have had to hack an event to pass the email provided into a hash field for a uid.

We've hacked the Reflection field to include the md5 function from the hash field...

I think it would be great as a checkbox feature in the Reflection field... thoughts?

Reflection field can use text formatters. You could extend it pretty easily with a simple text formatter for stuff like this (like I did just a few minutes ago ;).

Edit: Downside of this approach: Entries can't be filtered by the formatted/hashed value... :/