Free Hosting

While hosting plans can generally be found for less than $5 per month, free hosting can be useful if you're on a budget and have a low traffic site or are a hobbyist. A good free hosting provider will offer PHP, MySQL, email, FTP, and a control panel where you can manage everything.
Below are reviews of free hosting providers I have used.

000webhost.com

• used since Dec 2008
• lots of features and options managed through control panel
• domain suspended once for not enough web site visitors
• 2 domains cancelled for slow mysql query, no allowances! - I will no longer be using 000webhost.
• mail was down for a few days at least once, after which switched to gmail
• web server down infrequently for extended periods of time
• can use php settings directives in .htaccess files

x10hosting.com

• used since Aug 2011, when pegg.net hosting cancelled by 000webhost
• you must login to the forums at least once every 31 days to keep your account active
• can use apache directives and php settings directives in .htaccess files

heliohost.org

• you must login to your control panel at least once every 30 days to keep your account active
• can use apache directives in .htaccess files
• can use php directives in .user.ini files

Gmail

• limit of 10 users for Google Apps (free edition), used to be 50! - There is no longer a free edition of Google Apps!
• set your domain's MX record to ASPMX.L.GOOGLE.COM to use Gmail