I was in US only for 52 days in 2007 ( Nov 11 to Dec 31). I will stay in US in 2008 at least until my 183 are over. . Also note that I was in US for 331 days and hence a resident in 2006. So am I eligible to file for first year Choice ?

Understand that First Year Choice is for filing as a dual-status aline.

You can file as a resident alien ONLY IF you are married.

Based on the facts provided, you would file as a non-resident alien.

I am married. So you are sugesting that I can file for first year choice in 2007. I thought from reading IRS pub that I shouldn't be a resident in 2006 to file for first year choice.

Assuming you have a work visa and were married in 2006, then for 2006 you can file resident tax return.
In 2007, you don't meet Substantial Presence Test, so you will file nonresident tax return. You can't make first year choice for 2007 if you file 2006 return as resident.