Still a primitive tool (and based mostly on Scopus), but Scimago
http://www.scimagojr.com/ is yet another hint of the enormous
latent scientometric potential that is waiting to open up for us
-- if only we open up the data that we ourselves are providing --
(by mandating OA)! (Sample Scimago, and then also sample Citebase
http://citebase.eprints.org/, and exercise a little combinatory
imagination.)