I've had my tongue pierced for about a year now... I forget that I have it done about 99% of the time now. One thing - MAKE SURE YOU GET IT NEAR THE FRONT... the rear is what ladies get to give better uhm... yea. The front is for guys. (think about it) Now, had the lady told me this BEFORE I got it done, mine wouldn't be so far back. But she decided to tell me minutes after I got mine done. Also - it doesn't hurt.. biting your tongue is 100000x worse then getting it pierced.
Girls love the idea of kissing someone w/ a peirced tongue. Also, GET PLASTIC BALLS on the bar, and get a shorter bar... I chipped the inside of one of my molars w/ a metal ball... luckily it wasn't that bad. Also, biting on a metal ball HURTS LIKE HELL... Trust me on this. I'll even send you some plastic tongue rings for free just to make sure you use one. And just suck on a lotta ice afterwards, don't get slurpies like they told me to do.
As for talking... it effected my speech for about 2 days, and it wasn't even that bad. Just try not to eat for a day or so, and then only soups for another day or so.
If you get it, lemme know - I have more info on keeping it clean.