Then, just choose an alias and a domain, click Save, and you're good to go.
If it's available, you'll see a Cached link pop up under the title in the preview window to the right.
One of the best sites for finding them all in one place is Bug Me Not.
All you have to do is type in the URL for the site you want to view, and Bug Me Not will serve up a list of usernames and passwords for that site.
Clicking on that will bring up a snapshot of the page.
It may not have all the features of the regular site, but all the content will be there. If you use Outlook, Microsoft gives you the option to create up to five aliases a year for your account.