You can now create your own drawings inside Google Docs, and insert them into documents, spreadsheets and presentations. Be sure to check it out! All you need to do is go to the Insert menu and select Drawing.
Read more about this new feature in Google's official announcement at their Google Docs blog by clicking here.
Here's a drawing example from their announcement:
image from http://googledocs.blogspot.com/2009/03/drawing-on-your-creativity-in-docs.html
