Check out ScienceRoll is a metasearch engine geared for those in the medical community. It consists of several different search engine options along with organizations from which users can pick to conduct their search.
Clinical Cases Blog offers some nice options for customized medical searches. It discusses Google's offerings, but also highlights Science Roll (right), which says it's a better solution than PubMed.
Check out Scienceroll Search which is a personalized medical search engine powered by Polymeta.com. You can choose which databases to search in and which one to exclude from your list. It works with well-known medical search engines and databases and we’re totally open to add new ones or remove those you don’t really like.
An updated version of ToxSeek is now available (toxseek.nlm.nih.gov). ToxSeek is an NLM metasearch engine and clustering tool that enables the simultaneous searching of many different toxicology and environmental health information databases and web sites.
..we heard about a cool new Search Engine called PolyMeta.
NLM, DOE Synergy in NLM Prize for NLMplus – An Award-winning Demonstration of Semantic Search [presentation]
http://www.cendi.gov/minutes/pa_0112.html
ICE – Intelligent Clustering Engine: A clustering gadget for Google Desktop
Expert Systems with Applications, Volume 39, Issue 10, Pages 9524-9533, August 2012
Carlantonio, Lando M. di ; Osiek, Bruno A. ; Xexéo, Geraldo B. ; Costa, Rosa Maria E.M. da
http://dx.doi.org/10.1016/j.eswa.2012.02.101