Here is the solution BugMeNot.
BugMeNot is an internet service that provides usernames and passwords to let Internet users bypass mandatory free registration on websites. People share username and passwords of various sites that ask you to login to access that website.
How to use BugMeNot. Just visit the site(link stated above). Enter the website address for which you want login address and password. There would be a list. Select one among them. Yes there are chances that there would be wrong passwords(especially for well known sites like youtube which silly people often change). But overall it gives quite satisfactory results. For example I searched for slideshare.com and got the first one correct.
Check out this video: