Google has now added an SMS option for the password recovery of your google accounts thereby making lost password recovery an easy task. Right now this password recovery option via SMS has been made available in U.S only.
This is what google is saying about this new password recovery option:
It’s a busy world out there, and even the best of us forget our passwords from time to time. But we don’t want this to get in the way when you need to access your account. We also want to make sure that only you can access your account. Since most people use cell phones these days, we decided text messaging would be an easy, convenient addition to our password recovery options.
image credit: googlesystem.blogspot.com
For adding your phone number to your existing google account just sign in to your google account and then go to “change password recovery options” and now you can enter your mobile phone number there.
If somehow you lost your google account password in future they will send a code in the text message to your mobile phone number and this code will help you to regain your account password.