Learn Polish on your computer. The better programs (and more expensive ones) have enough
flexibility and feedback to (almost) make up for not having a teacher.
It's very convenient to be able to boot up your computer any time and practice your Polish,
drill in vocabulary and take quizzes in grammar.
Language courses on your computer challenge you with quizzes. You'll hear native speakers.
The software never loses patience with you.
Note: you can not return software to Amazon.com if you have opened the package.