Here's a quick way to see if an alternate, free copy exists on the web:
1) Go to Google Scholar.
2) Enter the FULL name of the article you want to retrieve, IN QUOTES.
3) Usually, the article you are seeking is in the first few results. Under the article's blurb, it often says All XX versions (where XX is a number). Click it.
4) Look at the links in the RIGHT column. There are often links directly to a PDF of the article that Google has spider'd. Make sure to check all of the page results to see if a PDF copy exists.
This technique saves me from opening up a VPN 85% of the time. If you STILL can't find a copy, try searching for the authors name and institution on Google-- often authors have a copy of the article on their lab website, or will be willing to provide you with a re-print if you e-mail them.
In the "worst case scenario", visit a university near you. Many of them have free WiFi which enable you to access journal subscriptions via Google Scholar, PubMed, etc.