Here's an idea that I have shamelessly lifted from another (not so friendly!) forum. Every week someone sets a theme (old school, Japanese, lettering, etc.) and people post their art work on this theme. Anyone can vote on which is the best one and the winner gets to choose the next week's theme. It is a good way of seeing how other peoples' work and styles compare and to give and receive useful feedback on what works and what could be improved. Anyone interested?