Can I choose to pay my taxes at the end of the year

Are you an employee?
Did you fill out a W-2?

This question can go in several different ways - so I'll take a shot at answering three questions for the price of one! Post back if none of these gets at what you meant:

1. Can I file my taxes at the end of the year instead of waiting until January 2010?

No - you will need your W2 and/or 1099 forms, and these won't be available for tax year 2009 until January 2010.

2. Can I avoid having any withholding taken from my salary, as long as I pay my taxes by the end of the year?

Generally no - employers are obligated to follow the rules for withholding, the amount of which is based on the number of allowances you claim on your W4. You can't claim that you are exempt from withholding unless you had $0 tax obligation last year, and will have total income this year less than $18.7 K (assuming married filing jointly; $9350 if single).

3. Can I wait to the end of the year to pay taxes on my income from investments, self-employement, gambling winnings, etc?

No - you must pay an appropriate amount each quarter, or you will be socked with an underpayment interest penalty at the end of the year.

Hope this helps.