Contribute to the Daily Doodle Club's free online art gallery. This cute website gives you a daily prompt such as to draw "an unusual awards ceremony" or a "koala knitting a scarf".
Next, you draw your image digitally using the tools on their website. You can make it as simple or detailed as you'd like.
Submit your drawing once you're content with it. I like this site mostly for the quick creative challenge it gives me, but it can be fun to see what other people come up with too. Although most drawings on there are very simple and scribbly, there's always a few people who have clearly put a lot of time into their drawings.
