journal impact

I nearly always use google scholar to search articles and I suspect many people who do research do the same. If your article shows high up in the search list depends, except for appropriateness of search terms and the year of publication, on how many articles cite it, how often these are cited and so forth.

The eigenfactors web site uses a method similar to pagerank in order to rate journals based on know how well connected their articles. You also find a map of connections between sciences and top ten lists.

For example, to see the impact of Annnual Review of Neuroscience, here is the Eigenfactor, and here the isi web of knowledge result (for isi web, you need to access from a licensed computer). The results look very similar.