In addition to individual citation data, Publish or Perish also compiles citation data for journals. I did not find the "Journal Impact Factor," a statistic that is often cited, but the program shows the H-index for journals.
Below are the rankings of a bunch of archaeology journals. This is a quick, non-scientific sample, done as displacement activity to avoid working on graduate student evaluations. The H-index is the maximum number of papers (say, "n") that are cited n or more times. For example, Amerian Antiquity has published 76 papers that are cited 76 or more times in the data from Google Scholar, while Radiocarbon has published 66 paper that are cited 66 or more times.
|Jr. Archaeological Science||65|
|Jr. Anthropological Arch||43|
|Journal of Field Arch.||34|
|Jr. World Prehistory||34|
|American Jr. Archaeology||31|
|Cambridge Archaeolog. Jr.||27|
|Jr. Arch Method & Theory||26|
|Latin American Antiquity||26|
|Jr. Archaeological Research||23|
|Gen. Anthropology Journals:|
|Annual Review Anthropology||94|
There are all sorts of factors that influence these data, and I am not any kind of expert on citation analysis. The thing that surprised me in these data are the much higher rankings of the general anthropology journals (these data include all articles, archaeology and other subdisciplines of anthropology). But I suspect that archaeological visibility (visibility to archaeologists) is higher for many or most of the archaeology journals than it is in the general anthropology journals. At first these data made me regret a recent decision to send a paper to Jr. Anthropological Archaeology instead of to American Anthropologist. My decision was based on a strict length limitation at the latter journal, and I didn't feel like cutting the paper. But I still suspect that more archaeologists will see it in Jr. Anth. Arch. than in Am. Anthropologist, particularly those archaeologists not trained or teaching in anthropology programs. And I am amazed at the quick turn-around time for reviews, revisions, and editing at JAA, which probably beats AA by a lot.
By the way, I never did find out my own citation data through "Publish or Perish" - I estimated that it would take an hour to weed out all the other ME Smith authors by hand. So I spent my displacement time compiling the journal data.