Back in May Zinio released a Web-based iPhone magazine reader which allows you to view complete magazines for free. To access it, simply navigate to www.zinio.com/iphone from your iPhone and you'll get free access to a number of popular magazine titles including:
Surprisingly, the Web app still works and it's still free. On their site Zinio charges US$5 for a single issue although you can preview the first 20 pages for free.
If you want to try it without an iPhone you need to change the user-agent on your browser. iSmashPhone provides links to simple instructions on doing this in both Safari and Firefox.