Do i need an external internet connection for ps3? (will answer your question)?

Made the decision to buy the ps3 for a multitude of reasons, the wifi and browser among them. i dont have an internet connection at my house, because i was able to get it free from an unsecured line on my laptop. i no longer get that unsecured connection, so im thinking about buying a network adapter unless the ps3 can connect buy itself. is this true or should i but the adapter? thank you.