Please don't do that! SBI has made its clients' accounts tech savvy, but still mistakes happen! All Bankers' now provide you an internet operating facility! You can transfer yourself from either SBI savings account or any other Banks' account to your PPF account. Marrying them up takes a day or two. Then it is in your finger tips.
Please don't bother about that internet frauds people spraed about as every bank has securitised their web site & you are safe in such transfers- I am doing for the last 11 months as I am old to visit banks. However, be cautious with your credit car payments to buy on Commercial web-sites unless proved otherwise--