Many of the posters wanted to eliminate money and so on.
Money is necessary at this stage of human evolution, as a feedback mechanism and an accounting mechanism. Money is simply a way of facilitating exchange, a way of rewarding productivity, a way of allocating resources, and even a way of keeping score. Any system without some measure for those things will be effectively random in its results, quickly overrun by freeloaders, and strongly subject to a mega-size "tragedy of the commons".
Worse, without the "keeping score" factor, there's no way for individuals to know how they are doing, relative to any external or intrinsic standard. While that complete absence of a measuring stick might work for the top-tier individuals who have already earned their way through a dozen levels of real competition onto Star Trek's imaginary flagship of the fleet, where there are literally no resource constraints and the ship will be rebuilt at the beginning of the next show, no matter what happens, it's unlikely to work on any world populated by a realistic cross section of anything we would recognize as human. (More about real human populations below.)
In systems where some other item acts as both reward and incentive - for instance academia, where degrees, publications and tenure provide the group and personal senses of status and value - you end up with gatekeepers and a nasty social dynamic where the mostly neutral place of the economically "token-gifted" is held by networks of the socially "control-gifted". In essence, you have high school cliques running the rest of your life.
The only counter-example I know of is the US military, which appears to have a status and hierarchy system that works in a fairly benign manner. Anyone care to have *everyone* live in that system the rest of their life? Anyone know any other positive examples that are open systems with a large cross-section of humans in them?
On the negative side, when tokens are the medium of assigning value and productivity, the people who get the most tokens are not necessarily the people who are the most valuable or productive, but are instead usually the people who are best at gathering and keeping tokens. This is a natural function of their aptitudes and motivations, and a necessary byproduct of a token-based system with choice and freedom of action. It's annoying to some, but it cannot be eliminated without losing the benefit of the tokens to the system.
Also, this side-effect of "bonus bucks to the token-gifted" is not in itself good or bad, regardless of what you might personally think of governments, bankers, developers, or other rich people. Over history, the token-gifted are the ones that funded everything you think of as culture and high art. Every world-class museum you've ever been to, every world-class city you've ever been to, and almost every human-made place you ever want to go, were all created via money from the token-gifted. As a rule, the Medicis were terrible people, but they funded great art. Same with the Popes, as near as I can tell.
There is this liberal tendency towards envy and false charity - the quite unliberal thought that no one can possibly deserve to possess and control billions (or sometimes only millions) of dollars, regardless of that fact that they themselves may have worked to create it, and scrimped to keep it. The liberal compulsively imagines all the people who have *not* earned it, but who need something that money might provide, so it's very natural for a liberal to want to *seize* from the rich to "give charity" to the poor, in order to make the liberal feel better about themselves. Bad idea.
First, when a person gives their own money, they can - and usually do - make sure that it goes to a place where it will be used effectively. On the other hand, when someone gives away money that they did *not* earn, they almost never take such care. After all, they say, "It's the thought that counts, and my intentions are good."
Second, if it isn't your own money, it's not your charity, and you deserve no good feeling from it.
I'd have to say that, given a few hundred million, I can think of quite a few problems that can actually be addressed, and the world can be changed for the better. But it wouldn't be by eliminating money, or taxes, or income, or anything else that gives people the freedom to choose their own paths.
REAL HUMAN POPULATIONS
In any system that permits diversity of thought, belief, behavior, motivation, and so on - and in most that don't - you will have diversity of thought, belief, behavior, motivation and so on. And each of those diverse people will use the system to accomplish their personal objectives, what *they* see as the best highest good. Or, if they are thoroughly thwarted by your system, then they will succumb to despair, or act to pervert the system toward their best good, or to destroy the system. If you want the greatest good for the greatest number, make sure that the heart of your system thwarts the most harmful and the least valuable and the least productive, rather than the least harmful and the most valuable and the most productive. And make sure that "harm" and "value" and "productivity" are objectively distinguishable.
In any realistic system, half the people will have below average intelligence. (By the definition of average, duh.) In any human system, a sixth of the people will be at least one standard deviation below the mean - in the US, that means an IQ of roughly 84, which falls under the current psychiatric designation of "Borderline Intellectual Functioning". Yep, one sixth of the populace, by definition, is mentally impaired.
**PLEASE** don't knee-jerk here. **PLEASE** put relative merit discussions aside for another day. Sure, we could engage in an entire series of cliche and highly charged comments about the high or low value of dull people, and about the value of certain productive dull people relative to the value of certain unproductive token collectors. **PLEASE** Just consider that we already had that whole thread, because the entire thread is totally predictable to people who aren't dull. You know what you'll say, you know what they'll say, and it has nothing to do with the point I'm making.
The take-home point I'm making here is that your utopia will need to address the needs and values of people at both ends of the intelligence scale. Try to make your Utopia work for the salt of the Earth as well as for the Heinlein characters.
UTOPIAS AND REAL PEOPLE
So, after your initial planning of your Utopia, make sure that you drop in some regular real-ish people who disagree with you and see how happy they are. Drop in a Christian surgeon trying to keep her son moral by her own standards, a Hindu streetwalker whose personal worth is built on compliments and presents by her regulars, an alpha male gay Mathematician graduating high school, a Muslim woman mourning the death of her six-year-old, a man whose self-worth is based on the operation of a fifth generation tire store, another man who is trying to build enough self-worth (and enough bling) to attract a particular mate. What do they think of your perfectionized world?