I had my tongue split about a month ago. We used injectable xyclocaine to numb the tongue, then, with a #15 disposable scalpel (in a sterile environment) proceded to split the tongue by piercing into it from below with the scalpel (blade forward) and then split it by cuting to (and through) the tip in one swift motion.

I felt no pain from the procedure(because of the xylocaine), but the feeling of my tongue laying open was interesting. Since then I've had to keep it from re-growing by scraping at it a few times a day (done with a sharp dentist's tool). The pain in keeping it open is minimal, but necessary to keep it open until it heals.

After having my tongue split my speech was noticeably affected, mainly because of the swelling and not being used to using the muscles of the tongue separately from each other. The swelling (and speech impediment) went away in about a week, though sometimes I still have problems with "D"s.

I've gotten some interesting reactions from it, ranging from disgust to amazement to wanting to kiss me just to feel my tongue (couldn't because it had just been cut, but soon :-). It is a very noticeable modification, just because it's visible when talking, eating, yawning, etc. I've enjoyed it, and am gaining more control over the muscles in my tongue. I can't spread it very wide yet, but I can hold onto things with it, including straws, pencils, toothpicks, and other similar objects.

In a few months I'll probably have my tongue webbing (lingular frenulum) completely removed, so that I can split my tongue back further.