Renewal of H1B visa before it expires

[Gandhi2010]

Hello,
I am currently on the first three year tenure of my H1-B visa. This tenure expires in OCT 2011.
I plan to go to india to attend my sister's marraige in march 2011.

My Question is:
1) Can i get my H1-B visa renewed and stamped before it expires on the passport.
2) when should be the right time to apply for my H1-B renewal?

Thanking you in anticipation

[sk4ih]

1) Why do you want visa when you already have it?
2) 3-4 months before expiry of current H1.