I looked for it on this site, but didn't find anywhere neither in downloads nor in forums. May be somebody have heard about it? Anyway I think this mod isn't difficult for coding, so if it does not exist I'll try to do it by myself...

The following threads might interest you:
* Topic rating system
* User ranking / Respect level ("Karma")
All best -
mb

so users ranking doesn't exist for minibb?

There is currently no user rating option, but user ranking is definitely supported: User ranking add-on (User rankings based on post count.)
All the best -
mb

(User rankings based on post count.)
no, that's not what i need. ok. i'll try to code it by myself and will share it hear, on this forum :)

Good luck with the modding, maxtat!
- mb

i think it's better to make a button "Say thanks" like on IPB. For storing two users' ids, topic's and thread's ids i'll make a new table. And number of said "thanks" i'll keep in user_custom3.
Only one question :) i wrote in a template for a test {$userInfo_user_custom3[$poster_id]} and created function function parseUserInfo_user_custom3($aa){return $aa;}
Huh, nothing happens :)

maxtat: you would need to define the displayed field in $userInfoInPosts option as well.

In general, I think what you have in mind is described in this thread:

Digging Posts

and it's not a "reputation mod" as you call it... but I may be wrong.

You're welcome to create only a qualified add-on, I usually remove all stuff which is coded more badly than for the middle school level.