For future reference: without the help of third-party apps, the answer is no. Text messaging (SMS) relies on cellular technology to work, and the iPod touch can't use cellular. However, iMessage makes it possible for iOS users (like an iPod touch owner with Wi-Fi) to "iMessage" another iOS or Mac users without using cellular. Of course its limited to just other iOS device users (any iPhone, iPad, iPod touch) or Mac users who have Messages installed.
Other third-party apps (like Skype as an example) can take "text messages" and relay them to cellular devices, usually at some minor cost.