Alright, I need this for trading reputation and no, I can't use ACP's reputation system, because I'm already using it for posts.

My idea would be that after buying something, buyer writes either +rep or -rep to seller's user wall. Then there would be a profile field or sth that would count these messages and display a number. Example:
Trades: 39 (38)
Format would be: All trades (Positive feedback aka +rep)

@JScript, I think that it could be done from your latest visitors script?

1- It could be, but we can not edit posts of the "wall" and the accumulation of posts will generate a new page in the "wall" ...
2- Could use a topic as database, but then comes another question that is make members into moderators!

But it is still a great challenge and I think it is worth it because we can turn this into something more...

JS

JScript wrote:2- Could use a topic as database, but then comes another question that is make members into moderators!

That's not a problem for me, I'm already using it for some codes.

@Tonight
Well, it's a nice challenge, this will depend only of my free time...
If I have a free time, I can do, or we can wait for another user to make it!

JS