Checkout ASCIIFLOW by Lewis Hemens a Software Engineer at Google in AdSense.
Embed flow drawings in emails, blogs and text based media. You can also share and save them as well as export your drawings to DITAA.
I intend to expand the site further to incorporate a gallery, and when core work has been competed I have every intention of making this entirely open source!
– Lewis Hemens
For development updates checkout his blog
Source on GitHub – Homepage – Blog – Hacker News
Linked by Adam Stacoviak on Feb 16, 2012