Recently, I've read through a number of proposals regarding systematic attempts to allocate labour in a post-capitalist society. Most of these share the common feature that they don't attempt to look in detail at true public goods. With a knowledge economy that is becoming an extremely large part of our overall productivity, I think this is an oversight which should be corrected.
In addition, there is a belief by many that open-source approaches can directly solve the problem even within a capitalist system. However, open-source suffers from a number of deficiencies. It does not demonstrate the ability to support the labour of people involved by providing them with livelihoods. It fails at providing necessary resources in the case of more capital intensive knowledge production, for instance chemistry, genetics, hardware manufacture or even cinema. It also is weak at signaling when labour is widely desired. This leads to a tendency to be hobbyist focused, being as it is only supported as a recreation, and not focused on providing the greatest public good.
A perfect public good is non-rival and non-excludable. A non-rival good means I can use it, and you can use it and neither of us experience any loss at the others use. Television and radio are examples of perfect non-rival goods. Internet tends towards being an imperfect, as do roads etc. Non-excludable means that it's not possible to keep you from using it. Street lights  are good examples of something which is very hard to exclude people from using. Knowledge naturally fits into this category provided we drop things like copyright and patent. Copyright and patent are designed in order to make a non-rival good appear to be a rival good by generating exclusion through the use of legal force.
In terms of efficiency the use of exclusionary force is purely a drag on the efficiency of the entire system. The drag on efficiency is partly due to the fact that it requires labour for enforcement - a judicial system, legal teams, police, methods of tracking use, incarceration or the levying of fines, the generation of DRM technologies, including software and specialised hardware - all of which do nothing useful (in fact they have negative use-value). In addition this enforcement has the extremely deleterious effect of reducing the free spread of useful information and concepts which can make production processes more efficient. In software and hardware there are huge levels of redundancy of research and "clean-room" designs done for no other purpose than to avoid patent suits. A new more efficient process will be kept intentionally limited in application in order to derive monopoly rents. Just looking at the list puts me in awe at the absurd inefficiencies of the capitalist system.
It's much more sensible in a post-capitalist society to treat these goods very differently. Since there is no (sensible) rivalry it doesn't make sense to try and charge some price for it. Still, in the immediate future it's not going to be possible for everyone to devote all their labour time to poetry or films. If these types of knowledge production draw voluntary labour to an extent that other basic goods production is not taking place, we need some way to see that this is happening.
Even if all labour were allocated voluntarily it would be exceedingly useful to see where labour was most appreciated to society - so unless we really and truly get to a post-scarcity society - it makes sense to worry about this.
The amount of resources that should be allocated for a piece of software, film, research and development or some other information based good is insanely hard to calculate. It requires knowing its labour cost, divide total popularity over all time - which is essentially impossible. We can however guess that the labour equivalent for a Michael Jackson song should probably be a microsecond of labour devoted from each of Michael's fan base. However, at the time of production it's entirely impossible to know this, since there is no way to know the amount of labour society would eventually like to devote. Indeed as time passes Michael Jackson's music may not reduce in popularity. Perhaps even more extreme, what value would we assign towards Newton's research into forces in physics?
If we want these sorts of endeavours to be supported beyond recreational labour and easily acquired resources*, then it makes sense to fund them socially. Past performance is no guarantee of future success, but it is some indicator. Social allocation could be described by looking at such performance.
Publicly funded information production is often done in a very monolithic fashion (but then so is private funding of films and bands in the main part). However, this need not be the case. The National Science Foundation for instance gives out grants to various institutions on the basis of evaluated past performance. It is conceivable that we could structure such an arts council and software council to do likewise.
The allocation of public funding itself might not be dictated by a board of experts as done with the NSF. It might be a delegated ministry of art/software etc, or it might even be possible to have a vote style infrastructure - which would allow people to describe the amount of their socially devoted production that should be alloted to various social goods.
The output of such an enterprise would not have to be policed in terms of consumption, but would literally be free access. By doing so it should be easier to institute methods of tracking the consumption as there is little incentive to avoid doing so. A post-capitalist youtube for instance would give good information about the number and multiplicity of views of a music video. Though it's impossible to account perfectly, and there are ways at avoidance of such, there is little incentive on the part of consumers to do so.
Because resources for institutions would be in some way tied to a reputation based on consumption, there *would* be some incentive for individuals who wanted to inflate their social importance to mislead. However, since there is no longer any reason for public funding of infrastructure like cinemas, youtube, or software repositories to have any connection with the content producers themselves, it's likely that it would be institutionally difficult to do so.
It's important to remember that individuals would be seeking the resources for necessary capital infrastructure and labour time, not pursuing actual profit. The profit motive wouldn't be a driving motivation in this scenario, even if it would likely drive certain individuals towards the reproduction of their status as reliable producers.
There are many possible ways of arranging knowledge production more cooperatively that could be explored as long as we keep in mind some basic facts:
1) Public goods are very difficult to value accurately even in a system of perfect information as they require knowledge from the future. Therefor no systematic approach is going to be perfect.
2) Public goods should not be treated like other rival-goods in almost any conceivable system of accounting. We should not create rival goods from non-rival goods by wasting resources simply so that they look like other goods.
When we work with knowledge, we should keep in mind that the model needs to be cut to fit the reality rather than the reverse.
* Think of the amount of time and physical resources devoted to Avatar or Water World for instance, and you can see the difficulty of arranging some types of knowledge production on an entirely ad hoc basis.
 Street Lamps were mentioned as a non-excludable public good by César De Paepe in his arguments with the Proudhonists.