If you have a challenge that you'd like to suggest to fellow Hubbers, where do you post it? I'm guessing it's probably in the forum somewhere, but the forum always make me feel a little bit lost, is there a special place for challenges?
When you enter the forum, you will see a gray column on the left. You will go to Hub Challenges in blue. Click to enter, you can then start a new thread with a challenge. I had posted a thread where people can submit challenges they make. You can go to either link here.