FWIW, ACM has something called ACM Authorizer that enables authors to post links to their papers so that others can read them without paying any charges to ACM.
You can already post your articles yourself, the Authorizer just helps you plug into the DL bookkeeping. And what's the point? What value do we realy get from the Digital Library these days? Its a feature that requires critical mass to be useful, and the fact that it is exclusive means it will never have critical mass.
Check out the latest CACM article on the open access issue:
Check out the latest CACM article on the open access issue:
http://cacm.acm.org/magazines/2013/2/160170-positioning-acm-...
I think the ACM is pretty much in denial at this point.