Hi.. I am working in the US on a H1... I have been here since January of last year... my wife who still works in India has come to the US on a Business Visa (B1) in November 2007... Can I apply for an ITIN Number for her and file for tax jointly for the Financial Year 2007?

Yes, you can file as residents Married Filing Jointly. You can do this even if your wife has never been to the U.S.

On your 2007 return, you will get standard deduction of $10,700 and exemptions for both of you and the kids. You will also get child tax credit of $1,000 each.
You must both declare your worldwide income for 2007. If you have any foreign income, and on that income you paid taxes in the foreign country, then you can claim foreign tax credit.

You will complete forms W7 (application for ITIN) for your spouse and children and attach with your tax return.
IRS Publication 519: Tax for Aliens.
You can contact AtlantaTaxExpert for your tax return [email protected]