Some websites requires to register to access their features.You can bypass them by following ways.
BugMeNot: Its the website which provides a platform to share passwords of such websites.You can easily get password of most famous websites.
Become a bot: Most of website allows the login protected content to be accessed by google bot/search engine bots to get listed in google/search engines.So lets become a bot!http://seebot.org/ and Be The Bot, other similar sites give this thing.Its is simply done by changing your browsing agent.
Google Cache: As I told above site allows google bot , so Google stores in cache.Simple! This trick works on famous expert-exchange forums too.
mailinator.com : Site like mailinator.com provides tempory mailbox,SO you can just use and throw mail id of the site to get registered.http://www.temporaryinbox.com/ is another such site