This is a great website to search Medline (Pubmed) on your iPhone. This site is also good on other PDA as well. To access this tool, go to the following http://www.unboundmedicine.com/medline.  Unbound MEDLINE contains citations to about 17 million medical journal articles found in MEDLINE® and PubMed®.

You search it using “Keyword” form to perform a quick search of MEDLINE/PubMed. For a more powerful search, use the Advanced or Best Evidence search form.

The Advances search allows to narrow your search down to. You have option to search by author, journal, date, language specific, publication type, etc.

The Best Evidence is good tool for medical student and physicians using evidence-based medicine. It allows you search specific for Therapy, Diagnosis, Etiology and Prognosis.