Flash Fiction challenges

One thing that really gets my writing juices going is challenges. But because I'm doing a big push to both graduate Grad school and finish my first 'real' novel I don't have the time to do too much in the full challenge forum. But real novel I mean something that I would like to have published, I have finished novels for NaNoWriMo before but those are/were tests to see if I could write like that. Well I can and I enjoy it. Speaking of NaNoWriMo my post next week is going to be about that. I miss being an undergrad for this one thing. In my writing classes we would challenge each other. My favorite class was my last writing course at the end of every class one of my classmates (or me on my turn) would give a flash fiction challenge before the next class meeting. So I would love some flash fiction challenges from my readers. To define Flash Fiction as I learned it 500 words or less. I used this to write my chapbook which is the base for my first novel. It was great way to get to know my characters and the setting. So please help me write my next book by giving me challenges. Challenges can be one word or a full sentence or two. Feel free to give me word limit or I'm just going to go to 500. I hope that some great challenges soon.