Blogger provides customisable themes and page layout options with an easy to use interface and useful statistics, but requires a Google account. Wordpress offers many open source themes, customisable design, widgets, good usage data and statistics, and user permissions. Tumblr allows different post types and has a simple social interface, though fewer features than Wordpress. Posterous is very easy to set up but has limited functionality and customization, posting by email with a mobile app.