[matheweis]

I run http://iconverticons.com/ on the side, along with the development of the corresponding Mac and Windows apps.

The University that employs me as a day job requires that I disclose any additional sources of employment or potential conflicts of interest... by that logic, I think I am obligated to disclose it. I do go to great lengths to make sure that I'm not using any University resources, don't do any work on the project while I'm there, etc.

My direct supervisor has always known that I develop apps on the side, thinks it's cool and it's otherwise not a big deal at all.

I think it's all about how much time it is taking and how you portray it. Is it a side project/hobby that you happen to make money on, or is it a fast-paced startup that you're spending 60 additional hrs of week on? Also, do you expect to have to leave your position soon, or are you still in for the long haul with your day job?