My prior judgment that most edited volumes in archaeology are close to worthless does not apply to conference proceedings. These are collections of papers from a conference, published soon after the session. Papers are short and timely, focusing on the issue at hand without extra space for the kind of posturing that most archaeologists can't seem to avoid. There is little editing and little effort to produce a nice-looking book. Proceedings serve the very useful purpose of making research available in print (and/or on the web) quickly and easily. There should be more, not fewer, such volumes in archaeology.
Unfortunately I can't think of any examples of published proceedings in my field, Mesoamerican archaeology, The Chac Mool conference publications at Calgary fit this genre, but the publication lag makes them less useful than they could be. I've given papers at several conferences in Mexico where the organizers claimed that the proceedings would be published (they insisted in receiving the papers quickly), but none have appeared after several years. My impression is that there are more such volumes published in Europe, and in America for Old World archaeology, but I could be wrong.
With easily available page production software (Adobe Indesign, Quark, Pagemaker, even some low-level Microsoft programs), one would think that conference proceedings could be done conveniently on the internet, with papers posted as pdfs as they are received and processed.