I just came across a site that offers free rapidshare, megaupload and deposit files accounts. But sadly the offer is applicable only in United States. So in case you live in US you are lucky but only one account is allowed per household. In order to get your free account all you need to do is make some referrals. You can choose any one of the following:
1 Month rapidshare Premium account- 4referals
3 Month rapidshare Premium account- 11referals
1 Month Megaupload Premium account- 4referals
1 Month Deposit files Gold account- 4 referrals
You can go here and get any one of the above account by making referrals mentioned above.