Yes, Amitabh Bachchan is now on twitter ! twitter bug has bitten BigB. You can follow him at @SrBachchan
His inaugural tweet was to Abhishek Bachchan -
And its a genuine account as he has posted on his blog informing the same.
So, follow BigB on twitter at @SrBachchan
(Thanks to @Srushtirao for h/t)