There are people who were born with the gift of drawing, others who managed to acquire it with hours and hours of practice and others, like me, who can spend hours admiring how a work of art is created from a blank canvas.
For the first two types of people there are a series of applications that allow us to draw on the web and record the process, leaving the video public with the step by step of what the artist has done, being a jewel for the third group.
I leave you with some options, some of which I have already commented on here.
flashpaint.com
Not suitable for beginners. There are styles of all kinds, in color and black and white.
sketchfu.com
We can choose the size and color of the brush and reproduce the video showing the process carried out during the drawing, which makes sketchfu a good option to learn techniques with other users who have shared their creations.
slimber.com
It allows you to draw using shadows, with which you can find true wonders.
twitdraw.com
The site is quite simple, it consists of a blackboard with six tools with which we can make our works of art, record them on video and send them to twitter.
colors.collectingsmiles.com
Colors Gallery allows any user to upload the drawings made with their Nintendo DS or iPhone / iPod Touch, allowing them to share the video of their creation with the rest of the world.