Hereafter is an enhanced version of orgtbl-ascii-plot.

Thanks, Nicolas, for your feedback. Enhancements you suggested include:
- let-binding (instead of setq)
- better support for table headers (correct parsing of 'hline)
- no dependency on cl-lib (hopefully achieving Emacs 23 support)
- use dolist (instead of mapc)
- clean up doc-strings

Have fun
Thierry