Watching free movies on the Internet is a cost-effective method for many people to keep up with the films that they love. However, there are a lot of issues with downloading movies off the Internet for free because it may violate lots of copyright issues. There are ways that you can still get movies for free without breaking any laws, though.
Find a site that allows you to stream movies. Streaming movies is different than downloading them because you aren't in fact owning the movies without a copyright, because the owner of the site has the copyright, and you are allowed to watch the movies. Sites like Hulu.com are popular destinations for streaming movies and TV shows.
Join a through-the-mail movie rental service that has an Internet component. Normally these services cost, but if you can join for a month or so when they'll waive the fee, you can get one month of free movies.
Find an online site that has paid downloading. Like the through-the-mail service, these paid sites often have deals where you can get a limited free membership that will allow you to download a single movie, or perhaps a small number of movies, before you have to pay any fees.