We like people who work on things for fun because it shows they really like hacking. That's why we have a question on the application form asking "what cool things have you built?" On the other hand, if someone were spending time on side projects during the first few months of their startup, that would be a bad sign.

I would say list them because it shows your team's ability to innovate. Besides, if Y doesn't like the one you submitted, they might like the other ones.

Cheers

'... I would say list them because it shows your team's ability to innovate. ...'

And I would say put a watch on them because their focus on their prime tasks may drop. If you are putting in your 100% where will you get the extra time?

It can't be that cut and dry. Creative people tinker with stuff. You want creative people. Obviously there is a point where side projects interfere with what you are trying to get done, but a "if you're working on anything else you're not giving 100%" attitude seems very short sighted.

'... if you're working on anything else you're not giving 100%" attitude seems very short sighted. ...'

Non core creativity kills startups quicker than lack of focus. Why? Because the core product will be making the money not a creative side product. Lack of focus on the problem kills your ability to make money. Look at from the business point of view (yuck, but thats what will allow future creativity).

Remember we are talking startups here, not established businesses. You simply do not have the time or resources. Now in the longer term you are correct. But make sure you understand each startup is in a fight for survival and it requires a very different mindset.

In the last week of 2006 and couple weeks before the launch of our site, I had what I thought was a great idea(thankyou2006.com). I shared the idea with my partner, he liked it, we worked on it for a day and launched it.

I had to break my own promise to not work on anything else. And it made me a little nervous that this might cause the distraction we didn't need few weeks before our launch.

Keys:

1. Know your and your team's limits from past experience. What has happened in past when you worked on side projects?

2. Find some angle where the side project has the potential to compliment your primary company. In our case, if the side project it would have given us some much-needed $$$s for our main start-up.

--Zaid

If you allow "much-needed $$$s" to determine what you work on, you'll never get your real project done. This is how consulting businesses are born (and products die).

Sure, that's why it's proceeds point #1:)

My team members enjoy creating things for the hell of it because it's fun. The application asked if we had built anything else. A lot of the things we are building is almost entering beta stage. I would say maybe 3 of the projects. We built it because it was fun to build.

We're concerned that Y combinator may think that we lack focused if we shared the projects on our applications. Should we or shouldn't we list the other projects we developed for fun?

Variety of ideas are indicative of the plasticity of mind. Rest assured, this is something YC will see as a good thing. Go ahead and list them.

While developing side projects, especially as a tool to your main project, you may come across something you may not have otherwise. Who knows -- one of these "cool side projects" may become the product you end up focusing on.