Are you looking for charting tool for your presentation on web pages ? Google Chart API may be just right for you.
Other examples of chart you can create.
All the examples above are created on the fly on google server. If you would do it from your web hosting account, it would have eat up a lot of your server resources. Why not just leave it to Google API chart ?
Restriction :- NO restriction, as long as you do not abuse it. No limit on number of times you call the API, but you are advised to inform google in advance if you use more than 250k times in a single day.
Check out the detail API on http://code.google.com/apis/chart/ on how you can use it.