Cool...learn something useful here.thanks all.
Yes, it is as simple as that, if you already have Gmail account, you already have about 10G of Google Drive space, just download the google drive and install on you computer(the USID and password is same as your Gmail account), then you will find a folder called "Google Drive" created in your computer, but must remember to configure to sync their sub-folders. copy few files into those sub-folders on your computer, give it sometimes to sync then go to Google Drive website to check and ensure that they are uploaded. I was the early adopter of Google Drive, I paid US$20 a year for 80G cloud storage and I don't know why I am having 96G space now.
As for Skydrive, after creating an Outlook Email (Hotmail) from Microsoft, it also come with 7G of Skydrive cloud storage.
I choose Google Drive and Mirosoft Skydirve because these are big players that I don't believe they will "fly by the night" and disappear.
I also have more than 100G of cloud storage from Dropbox after buying Galaxy note 2 and Galaxy SIII Mini, but only use a few hundred Mbytes for sharing files with friends. I don't rely on Dropbox as my primary storage is because I also worry that one day they might just decide not to continue the service.