You can use jQuery Sparklines to easily create line (default), bar, tristate, discrete, bullet, pie or box charts. Each type of graph that it creates offers customization options. Some of the common options that are available in all chart types include: width, height, colors, minimum and maximum range.
Developed by Gareth Watts for Splunk Inc; jQuery Sparklines is available for download under New BSD License. You can find further information, demo & download on jQuery Sparklines.