I thought I better clarify something as there have been several threads on this now...
I posted a story about "betting" with my 8-year-old. There is a COMPLETE difference between teaching a child what a "gamble" is and teaching a child how to "hustle"...the latter I would never do, as I don't believe in taking advantage of others and it's not something I would ever teach my child...period!
We "gamble" in everything we do...walking across the street is a "gamble" that we're not going to get hit by a passing car. We can minimize that "gamble" by looking both ways when we cross the street...that's what we teach our children (or at least it should be

). So, in a very far-reaching analogy, this is in a sense teaching our children how to minimize risk while "gambling". The same can be done on a pool table...if done properly.
Teaching a child that you should "never make a bet if you can't pay the debt", is teaching responsibility and taking ownership of one's own actions.
It can teach "risk - reward". Again, something that we as adults deal with on a daily basis!
Making a wager on a game of pool with a child is different than betting on a UFC fight (honest to gosh, no offense to the OP in the UFC thread - I thought it was a cute story). Betting on a UFC fight, neither party has any direct input as to the outcome. Betting on a game of pool, both parties have a "say" in what happens in order to achieve the "win". This can teach a child self-confidence and to believe in himself/herself.
The most important thing if you're going to use gambling, wagering, betting as tools to teach "life-lessons", that you need to approach it with the positive lessons, and not the negative ones...if done properly, I don't feel there is anything wrong with utilizing gambling as a teaching tool. Every child/adult has a different learning style (whether it's watching someone, reading a book or hearing it verbally)...the same applies to teaching...there can be different styles of teaching and gambling (again, if done with a "positive" end result in mind) is/can be just one more tool in teaching...
Jason