It is sometimes (but not always) possible to bypass website registrations using the Google cache. This only works if the site allows Google to crawl their site unregistered, but you'd be surprised how many sites actually allow this.

To start, you need to find the page you are looking for in Google search results. This isn't too hard since Google allows you to perform site-specific searches. To perform a site-specific type in the following:

site::www.sitename.com search criteria

Where www.sitename.com is the domain you want to search, and search criteria is some search criteria that will result in the target page being returned in the results.

Once you have your page, click on the 'Cached' link in the results. This should show you the cached results for that page.