Google Scholar Citations (currently in beta)

"Launched in 2004 as a search engine for academic publications, Google Scholar last month added Google Scholar Citations (GSC), which lets a researcher create a personal profile showing all their articles in the Google Scholar database. The profile also shows plots of the number of citations these papers have received over time, and other citation metrics including the popular h-index, which attempts to measure both the productivity of a scientist and the overall impact of their publications. The service is currently in invitation-only beta testing, but Google intends eventually to roll it out to all researchers."  Read more at Computing giants launch free science metrics.