All operator balance transfer trick

Airtel
Simply Dial *141# and follow the instruction

Docomo
Type a SMS as BT MobileNumber Amount and send it to 54321,
e.g. BT 7200000054 25 to transfer Rs.25 

Idea
type a SMS as GIVE MobileNumber Amount and send it to 55567 
e.g. GIVE 8123546789 30 to transfer Rs.30 

Uninor 
Just dial *202*MobileNumber*Amoun#
e.g.Dial *202*8123456789*20# to transfer Rs.20 

Vodafone 
Just Dial *131*Amount*Mobile No#
e.g. *131*50*9123456789# for transfer Rs.50 

Aircel
Now u can transfer the aircel Mobile Balance Officially DIAL *122*666# 
You can transfer 10, 20 and 100Rs

Reliance GSM
Step 1: Dial this number *367*3# 
Step 2: Then enter *312*3# and mobile (mdn) number 
Step 3: Enter the amount you want to transfer 
Step 4: Enter the pin.default pin is 1