Allow a user to flag the same node/user multiple times The flag module allows flags to be defined per user.  For example, User 1 can flag Node A and B, and User 2 can flag Node A but not Node B.

In this situation, a flag is either on or off per user.  However, is there a way to allow a single user to flag the same piece of content multiple times?

Use case: I have created two content types, Message and Reply.  I want to limit the number of times that users can reply to a message (say, to 3).  To do this, I was going to use Rules to automatically flag the original message each time a user writes a reply.  However, since content is either flagged or unflagged, I don't see any way to allow a user to flag the content multiple times.

Any ideas on how to approach this use case are welcome, including using modules other than the flag module.
How about using the Five Star module and incrementing the rating each time?  Eg, first reply, rate the message 1.  Next reply, re-rate the message 2.  When you get to 3 (or 4 or 5) don't allow more. You could implement this directly with the Voting API if you wanted to, too, I'd imagine, if you needed higher than 5.