BioMedSearch was just reviewed in The Scout Report of the Internet Scout Project - excellent timing as we celebrate Science and Health during December in the Year of Science.
BioMedSearch is an "enhanced version of the NIH PubMed search that combines MedLine/PubMed data with data from other sources to make the most comprehensive biomedical literature search available. BioMedSearch also provides advanced account features that allow saved searches, alerts, saving documents to portfolios, commenting on documents and portfolios, and sharing documents with other registered users."
The cluster concept is interesting, bringing together papers related to one of 100 broad topics. Scanning through the top list of clusters is relatively efficient, but the subcluster lists (each with another 100 closely related topics) are harder to differentiate as many of the defining terms are repeated. Take a look at the population genetics subclusters, for example.
This maybe perfect for someone who needs an efficient way to follow all new publications in a specific area (polymorphism in schizophrenia, perhaps), and registering for BioMedSearch is free. Give it a try!