You can get most physics-related materials from regular document delivery sources (see "Document Delivery Services"). Alternatively, check to see if the article is posted free on the Los Alamos "arXiv.org" e-Print archive (http://xxx.lanl.gov/), and/or use a good search engine to try to find it on another Web site.
To search for articles on a particular topic, by a particular author, etc., use Physics Abstracts. An online version is included in the INSPEC database, available in Dialog.com Files 2 (1898-present), 3 (1969-present) or 4 (1983-present). A back-up choice would be Scitation or one of the services discussed in the Science and Engineering entry.
If you have a question about everyday physics, Lou Bloomfield at How Everything Works will try to answer it for you. The Argonne National Library host an Ask a Scientist page where you can ask physics questions.