> 1. Have you incorporated?

No I operate as a sole proprietor.

> 2. Do you pay quarterly taxes?

Nope, I pay the penalty since my income and ability to shelter it vary from year to year. The penalty is something like 3% on the total taxes you owe. Not too bad given the flexibility holding your money provides. Maybe I can load up a i401K that year or need to save for some big purchase which is more valuable then just giving the IRS the money.

> 3. Do you list it as other, unreported income on your returns?

I file a Schedule C

I do it all using TaxAct. Super easy and cheap. Helped me to understand taxes as well.