If they are talented and interested in learning, I could work in the opposite direction. I am leading a team of 5 people, and as in your case our work is project driven. I try to keep all team focused on the project needs, and whenever we can get to use a not well known (for us, that is) technology the person that is most interested gets to try it, get it to work and later explain the pros and cons to the rest.
Of course, everyone will not have the same amount of expertise as the person working out the problem, but the good thing is that a person interested in a technology will learn it better and faster by themselves than someone with a lesser interest. And later on, once they do know it they will sell it to the team better than any docs. This sessions usually end up in discussions about limitations or possible uses of the technology that the first adopter did not consider and a following iteration. This sessions are quite informal and usually short.
Usually at this point there will already be a couple of people interested, the first adopter and whoever came with the new possibility or limitation. More often than not, at this point everyone is interested in knowing about the outcome of the experiments/investigation.
While this clearly takes some time out of the pure project development, the cost is usually small compared with the advantage of spreading the knowledge among the team.
In Spain, development is a field where people switches jobs quite often, companies do not pay too well and the only way of minimizing the turnover is keeping the interest of people in what they do. At the end, you know that your people will quit at some point and shared knowledge reduces the cost of leaves.
As a final note, that works for me mostly because of the team. You need enthusiasts in what they do. At least two to startup discussions. Then the rest will probably get in the mood and follow up. But that is not something that can be pushed from above. It can be encouraged, but it has to happen in the team.