Every year, disputes arise about where and when the moon was sighted, and on which day Ramadan begins and ends.  It is advised to check with your local mosque and fast with your local community.  Check these sites for listings of mosques, Islamic centers, and prayer times for your local area.

Prayer Minder Online
Choose your city among hundreds around the world, plug in a few variables, and this program will display a prayer time chart for your locale.

Islamic Finder
Locate mosques and Islamic Centers in the United States.

Mosques in Canada
Directory of mosques and Islamic Centers in the Canadian provinces.

Muslim Directory - UK
Searchable directory of Muslim businesses, organizations, and mosques in the United Kingdom.

Islam in Australia
Links to Australian Islamic organizations.