Hi, my new iphone 5 is ratting when i tap on the top half.

Normal.

I've noticed this and it does impact on the sense of quality of the iPhone 5 in my opinion. I keep worrying that there is something loose and broken inside the phone everytime I feel the rattle. Good to know it's normal, I guess.

Same issue here, iPhone 5 rattles, not sure what else to refer to it as, near the top part of the phone.

Yeah, the thing is, it didn't rattle when I bought it (same for most I've talked to about this) and then suddenly, after a few days/weeks, it rattles. It might not have any impact on performance, but simple logic says that something that was tight is now lose. And for a 5000 DKK phone that is not good enough.

Some people had similar issues with the 4S, and it was suggested that the rattling sound comes from the gyroscope/motion sensor that is sitting a little bit too lose in it's mounting. Sounds plausible.

Anyway, I object to this being "normal", even though it's only in a descriptive sense. It might be happening to a lot of iPhones, and in that sense normal, but it really, definitely shoudn't be!

Also, my rattling sound is now much heavier and louder than when it first began. So not only has something tight come lose, it's also getting more lose with time. When will some function stop working?

Same issue here. Had it checked out at Apple Store in Tysons, VA yesterday and they opened it up to check it out and compared it to other phones all just to tell me "normal" and that is just the way it was designed. I have had every iPhone since the original and I must say this drives me batty. It makes our slick phone sound plastic and cheap, and certainly does not give me the sense of comfort that it will last a long time without something breaking inside.

This rattle gives the impression of poor workmanship or quality control and when I get a text makes the phone rattle especially poorly. Not good and I'm not happy.