I' am moving some money from 401 k to a ROTH IRA account and the money is before tax money I understand that the tax can be split between to years in 2010 and 2011 when this is done if I move it this year

You will pay ordinary income tax on the difference between the current market value of your 401(k) on the date of transfer and the "after-tax" amount of your investments. For most people, the "after-tax" investment is $0, so in effect you pay tax on the full amount.

Yes , you can spread the amount over two years. This option to split taxes over two years applies ONLY to conversions made in calendar year 2010. If you take this option, you pay half the taxes due with your 2010 taxes, and the other half with your 2011 taxes.

Couple of other things - you say you are moving "some" of your 401(k) to a Roth IRA - but actually you must convert your 401(k) account in its entirety. And the cash that you will require to pay the tax bill can not come from the 401(k) itself - it must come from other sources.