Conclusions: Interactive and collaborative web applications undeniably offer new opportunities for reaching patients and other health care consumers by facilitating lay information creation, sharing and retrieval. However, researchers must be careful and critical when incorporating applications or practices from other fields in health care. We must not easily dismiss concerns about reliability as outdated. Specific issues related to use of newly popular web applications for health purposes must be addressed. Nonetheless, the articles reviewed here also clearly show that potential problems can be addressed and the positive aspects of the technologies embraced. (Source: International Journal of Medical Informatics).