Yesterday I challenged you to exercise your creative thinking muscles by listing 10 ideas for new businesses. The point of the exercise was not to come up with good business ideas, but to exercise your mind, which just like your body, gets stronger when you use it in new ways.

A couple of you took me up on the challenge.

Keeley Tillotson (full disclosure: my super awesome girlfriend) did a 15 minute brainstorm and posted it on her blog. Definitely worth a read. Here's one that I especially liked:

Art printing platform that allows young age 18-and-younger artists to upload high-res images of their art — so anyone can log-on and purchase beautiful prints (from family members to community coffee shops to people who just want to buy great artwork from young people). Young artists get high percentage of the profits.

How awesome would that be? Who wants to build it?

Another reader, Jacob, sent me a list with not 10, but 13 ideas! It included perhaps the most offbeat idea I received:

1) A film production company that produces all experimental short films of stories by Jorge Luis Borges."

The great thing about the internet is that a company like that could actually make money, by charging $1.99 for a download on Vimeo, and being the only place for fans of Jorge Luis Borges to see high quality, experimental shorts adapted from his stories.

Jacob also sent along this whimsical idea:

2) A food train- hybrid of a food truck and a traveling circus- each car a different restaurant or food vendor.

I love all the creativity!

I said I would share my brainstorm if you shared yours - so as promised:

My brainstorm of 10 business ideas:

1. An easy-to-use integrated loyalty system and email automation for grocers. Working in the grocery industry, I can safely say it is a bit old fashioned it certain ways. Customers should be receiving customized, relevant deals and news based on their previous purchasing habits just like they do from Amazon. Not just one-size-fits all blast communications. This is possible, and some do it, but currently it requires too much money/human capital and doesn't have great UX.

2. An affordable, subscription-based campaign fundraising, tracking and persuasion software that is sleek and easy to use. Tracks your prospects, gives you reminders, scripts, and more. Having worked in campaign finance before, I believe there is a definite need.

3. A non-profit that builds playgrounds that are engaging, big wonderlands. They would be way better than most current playgrounds - not static, but ever evolving based on how kids choose to build/use the space. A small hint of danger and struggle may event exist. Give those kids grit!

4. A travel photographer who follows people or families who hire them, but at an unnoticed distance with a zoom lens, so you get a bunch of candid photos of your family vacation and feel like a celebrity getting followed by paparazzi all at the same time.

5. I'm a daily Evernote user. I use it to save and categorize all content and ideas that I want to be able to easily reference in the future. I'd love an app that compiles all my Evernote notes in beautiful, categorized printed booklets and mails them to me. Customizable or automatic.

6. Intensive camps for adults that fit a variety of schedules. I'm learning Tennis this year, and I have access to private lessons, group once-a-week classes, or the ball machine. But it's the kids that really have it good. They can sign up for a week long, 9-5 intensive tennis camp. I WANT THAT! I'd like to see more 2 to 14 day intensive camps for adults in a variety of areas.

7. A game for mobile devices called "Fish Ladder" where you play as a salmon trying to swim up a fish ladder. There are obstacles, various strengths of water flow, fisherman, and a variety of things to avoid as you navigate the salmon to safety!

8. An app that turns your smart phone into a "dumb phone" that can only do phone calls and emails for an amount of time that you set. While it's active, there is no way to reverse your decision and deactivate it.

9. A film production company that makes live action, non-animated, dark, adapted remakes of classic books or animated films - such as Hansel and Gretel, Aladdin, Cinderella, James and the Giant Peach, Little Red Riding Hood, etc.

10. Professional photographers are too expensive for a lot of people who just want to get a good headshot or portrait done. I would like a robot photo studio, where you pay like $20 to enter, step onto a green screen stage, and then listen to automated announcements asking you to smile, be serious, etc as 10 different high def cameras all around you shoot 100 photos automatically in 30 seconds. A computer algorithm then removes all the photos with eyes closed, etc. and sends you the rest in an email with a standard solid color background of your choosing. You can pay extra for cool backgrounds like a brick wall, or standing in front of the eiffel tower or something.

There you have it. Some of these are a bit silly, and some would probably be a complete failure with no paying customers, but it's a fun exercise.

Give it a try. And if you feel like you have no good ideas, you have even more reason to exercise your creative thinking muscle.

And don't forget to send me your ideas or post them in the comments.