Freelancers: Pay Your Taxes
petekeen.net
petekeen.net
Basically if you can hold onto the money and save it; the interest can make it easier to pay the IRS.
... It's not like the IRS will give you interest if you pay quarterly; or a cut of your taxes.
Lastly, it's stupid to overpay your taxes thinking your going to get money back from the IRS. Put it in an bank account and get interest.
Maybe an unpopular opinion, but I'd rather be safe and in the IRS' good graces than try to earn a margin on their money net of their penalties and interest.