Print that link out and keep it on file, as it does a great job in laying out the Biblical foundation for languages as a sign of God's judgment. Yes, tongues is just a sixteenth century word for languages. Why it's in modern translations, I'll never know.
There's no need for the sign anymore. It's primary purpose has went and gone. The secondary uses that were necessary to keep it Biblical went with it. One of the main reasons tongues were spoken at Pentecost pointed towards A.D 70. God's judgment on Israel. Tongues were also spoken to show by way of miracle that God's "Promise of the Father" that was owed to OT saints was being given, the NT indwelling that all Christians receive the moment Jesus places the Holy Spirit in them, called the baptism with the Holy Spirit. For Jews and Gentiles alike. It also showed that God was undoing the confusion of languages that He caused way back in Babylon so that the Church could preach the Gospel to the whole world. It's a unique time in history and should not be used to form doctrines from because the circumstances are unrepeatable.
What you see and hear in modern churches is not the Biblical gift of tongues. In fact, it has more in common with Babylon. What they have done is they have taken all the rebukes by Paul in 1 Corinthians, the 'what not to do's, and read them as the 'what to do', and have in many respects, recreated the mystery religions of Paul's day.
Dave