Pollstar

http://www.pollstar.com

Useful for seeing which musical artists or comedians are coming to town, Pollstar is a consolidated artist tour schedule that allows you to view by artist, city or venue. Pollstar is a major agency which charges for inclusion in its lists, and the artist or venue you're looking for must be a paying member to be included. Their most useful feature is an e-mail notifier which alerts you when changes to an artist, city or venue on your list of interests occurs. Free accounts allow for up to 5 notification watches. Note that it's always a good idea to check the website(s) of the artist and venue, as discrepancies in content or posting time for different websites does occur.