There are many different services to facilitate the life of a web developer or designer, including creating various charts, diagrams, flowcharts, etc. Below is presented a small selection of them. They'll help you greatly while making a mind map, developing schema of customer relations and other.
All pictures are clickable and lead to the appropriate resource.
Amcharts — a set of flash-based charts for websites. Can retrieve data from a CSV or XML files, can also receive data generated dynamically using PHP,. NET, Java, Ruby on Rails, Perl, etc.
Best for Charts. Used to construct various kinds of charts and diagrams.
Allows you to create various graphics for websites, blogs, profiles, etc. It may be useful for visualizing scientific, financial or any other information.
Flowcharts, various organizational, hierarchical charts. Supports export to PDF.
Supports drawing a set of objects (of lines and triangles, to Bezier curves), and exports to PDF or PNG.
Excellent service for creating various diagrams, very nice-looking interface and many features.
Allows you to create and edit charts ties.