Staph aureus. This organism which many of us have as normal flora, can be a very bad actor. It has the potential to create infection in any part of the body, including endocarditis, pneumonia, pyelonephritis, osteomyelitis, septic arthritis, abscesses everywhere, including the skin and soft tissues. Interestingly, it is not a common cause of sore throat.
Sinusitis. In addition to the other correct answers already given, i would like to add the frequent occurrence of this bacteria associated with chronic rhino-sinusitis. Furthermore, this bacteria can release exotoxins which in some cases, can lead to up-regulation of lymphocytes in the nasal mucosa, so called, super antigen hypothesis for the etiology of chronic sinusitis.