You have probably already noticed that records in Google Scholar include links to articles etc that cite the work referred to. Click on the 'Cited by...' link and you get a list of works which cite it.
You may have also noticed that the works with the highest number of citations are generally higher in the results list than those with fewer citations. The reason that this is not always the case is that Google puts a higher weight on citations which have themselves a high number of citations. This is the same way as Google works, where referring URLs are used rather than references.
Although launched on April 1st, the Google Scholar Metrics for Publications is (I think) a legitimate service from Google. It takes the citation data already available and uses it to rank publications, in a similar sort of way as that available with the well-established Journal Citation Reports (JCR) or the alternative SCOPUS.
However, whereas JCR only looks at the most highly-ranked journals, the advantage with Google Scholar is that a much wider range of journals are included. You can have a look at an example for 'cinema OR film.' One major problem, though, is that you can only group journals by words appearing in their title - thus missing out Screen and Cineaste from the example given (a list with them included is available here). This makes the service interesting, but in need of development.
In a similar vein, Google's previously announced 'my citations' service allows you to create a profile and track works on Google Scholar that cite works that you have authored. You can then make this profile public if you wish (see Albert Einstein's profile for example), or keep it to yourself. It is very easy to set up: go to 'my citations,' type in your name, affiliation, email address and areas of interest and then varify the list of publications listed. It really is very easy and is recommended for academics who wish to promote their work (which is anyone who has published I guess).