A few places in the net...

Google
Search engine that can also help you search maps and images.
Google also provides other free services like email, translator, pictures server, website creator and much more.

Skype
Very popular instant messenger with voice calls, video calls, screen sharing and monthly subscriptions for unlimited calls to phones and mobiles.

iTunes and iTunes U
iTunes allows you to purchase music and TV shows as well as purchase or rent movies.  iTunes U has free university lectures on verity of topics.

AutoHotKey
AutoHotkey is a free utility that can do "almost anything" by sending keystrokes and mouse clicks.
For example you can automate opening websites and other programs that require logging in every time you use them.

JakDojade
Public transportation website to find connections in Warsaw.