• Database integration/conversion
• Data conversion/migration/encoding/decoding/analysis
• Implementing a (new) protocol
• Be the (new) maintainer of a CPAN project

Or do all of these classify as "real" application in your list?

Hm, not sure. I definitely forgot data munging. "CPAN project" can be dereferenced to the project's purpose, so isn't something I would put on the list. I was mostly aiming for typical beginniner projects so new protocol would probably be an "other" (who jumps in and implements a new protocol in a language they don't know? and if they do, "other" and bragging in the comments is appropriate :-). Perhaps "real user application" and "real infrastructural application" should be split?

Perhaps:

First memorable perl project
 - webpage
 - scientific
 - system/database administration
 - game
 - data munging
 - "toy" utility (task manager, chatbot)
 - "real" user application
 - "real" infrastructural application
 - other

Good Day,
    Dean