Speaking in tongues can be a gift from the Holy Spirit- in this case it is not gibberish, but is actually actual words of another language spoken through that person via the Holy spirit---be it another human language, or a language that does not exist on this earth. Some say that many who speak in tongues are speaking a language of the angels... or maybe another intelligent race on another planet , for all we know.

The key is, that these words honor the Creator-- and at the same time, they heal the person's soul when the Holy Spirit speaks them through a person.

Not all have this gift. Many think they are speaking in tongues, but it is not from the Holy Spirit- but from an entity or spirit using their mouth.
Also, God does not give this gift to the curious, which is why most of Christianity today doesnt speak in tongues.
It is a gift given only to those who sincerely have devoted their souls and lives back to God- out of love to Him and not for what they can get from Him as some form of "Santa Claus" provider.

I do not have this gift. Maybe one day at my death bed, the Lord may give it to me. The important thing is that He becomes the main focus of my life- and whatever He wants to give me is for Him to decide the "when & where". My pastor mentioned that some may never receive this gift until after they leave their body after death- God has good reasons for each individual.