Do you want to improve your immersion environment for the language you are learning? Well, clearly you use a computer, and if you’re reading a blog post, that probably means you use a computer a lot. In two minutes, you can change your computer’s environment so that you are being exposed to the language you want to learn whenver you are on your computer. Just change the language your operations system communicates with you. This has been suggested before by AJATT (see #5), among others. But in case you don’t know how to do it, here are some instructions for a Mac running OS X, Leopard or Snow Leopard (perhaps earlier versions too).
First, open System Preferences. You’ll see a window that contains the following:

Select the International icon in the top row. You’ll see this:

In the panel on the left, drag the language you are learning to the top. If you’re learning Japanese, it will look something like:

If the language you are learning isn’t in the list, click the Edit List… button to get a list of all the available languages:

Enable the language you want. Back in the original International window, the new language should appear. Drag it to the top to make it priority number one.
Close System Preferences.
The next time you restart or open an application, its interface should be in the language you just made the top priority. You need to relogin to see the changes in the Finder.
Many applications, such as web browsers, will pick up on the change you just made and certain websites (Gmail, for example) will also be in the immersion language.