Ed Felten has the first report (unfortunately, I wasn't invited) that I've seen on the Berkman Center's Speed-Bumps conference (What is a Speedbump?). Apparently there was legitimate disagreement over what, exactly, a speed bump for digital distribution is. Felten rightly faults one vision of speed bumps, but I believe his alternative definition is also too broad. The faulty concept:
One vision of speedbump DRM tries to delay the leakage of DRM'ed content onto the darknet (i.e., onto open peer-to-peer systems where they're available to anybody). By delaying this leakage for long enough, say for three months, this vision tries to protect a time window in which a copyrighted work can sold at a premium price.
As Felten explains, this vision (usually associated with DRM) is unworkable. I've written more on why it makes little sense here (Speed Bumps on Your Car)
Felten is right that we have to think about "speed bumps" in another fashion, as impediments to illicit filesharing. In other words, make it inconvenient to download/share music illicitly and make it convenient to do it legally:
A real speedbump doesn't stop drivers from following a path that they're determined to follow. Its purpose, instead, is to make one path less convenient than another. A speedbump strategy for copyright holders, then, tries to make illegal acquisition of content (via P2P, say) less convenient than the legitimate alternative.
This is the approach I've advocated all along, generally referring to it (somewhat misleadingly) as "carrot and stick." Raise the cost (time, convenience, legal bills) of illicit filesharing and lower the cost of legal filesharing (lower prices, broad library, open formats). Once the cost of illegal filesharing is more than the cost of legal filesharing, people will choose the legal alternative.
It is important to realize that there are different costs for different demographics. For example, college students generally have more time than money. The costs to them of searching through spoofed files for a good rip are lower relative to the costs of a harried thirty-something who is actually earning a salary. The issue is to design systems that raise or lower the appropriate costs for particular demographics. In the example above, one policy response might be to increase surveillance of and legal attacks on filesharers at university ISPs (raising the costs of illicit college student sharing) and/or to provide reduced prices for legitimate files to university ISPs (lowering the costs of licit college student sharing).
Of course, this is obvious. Any system is going to have to make legal access easy/cheap and illegal access inconvenient/expensive or it isn't going to work. Even the "Alternative Compensation Systems" are simply variations on this basic rule.
However, I think such a concept of convenient/inconvenient is too broad to simply call it a "speed bump." To be a speed bump in the sense, I believe, that Charles Nesson (a major proponent of speed bumps) initially intended, the inconvenience factor is going to have to be time-limited to an interval in which the protected work captures a significant portion of its market. So, for example, most copyrighted works make a majority of their money a short time after initial release. Thus, a "speed bump" approach would increase costs significantly for illicit sharing for a time-limited period shortly after initial release (such as Nesson's proposed self-help for a few months after release). Alternatively, one might reduce costs for initial release and charge more for access to older works (not necessarily as insane as it sounds. See, Outside the System: The Valley Cost Model: Broadcatching and Net Television).
Speed bumps, in my view, are merely a subset of the broader relative convenience debate.