This page provides links to some conference listings. Many of the listings provide an alerting service.
A wiki for Calls For Papers in science and technology - lists around 15,00 CFPs
Calls For Papers website compiled by University of Pennsylvania (Dept of English)
Conference Alerts: Academic Conferences Worldwide
Browse Conferences by Topic or subscribe to this free service to keep informed about upcoming conferences
Conferences in higher education and related fields
Innovation and technology
News lists, including conferences
Find academic announcements and calls for papers
Institute of Physics
There are vetted tools to help researchers identify recognised conferences in their respective fields. Further there are conference portals and -directories (created by commercial companies with interests in promoting the conferences).
Always evaluate information sources used to make strategic decisions carefully.