House Elves Apparating

No-one else seems to have noticed that the House Elves can apparate and dis-apparate inside Hogwarts when no-one else can. Dobby seems to come and go at will even in book 6. When the students wanted to learn apparation they had to do so in one specific room where the ban on using this mode of transport within Hogwarts had been temporarily lifted just for the duration of the lesson.
Is this important or am I just too involved. I just wondered if House Elves are more powerful than they seem to be. Dobby seems to be able to do loads of magic, i wonder whether he might have some role in helping Harry rid the world of Voldemort in the next book. (That's if Dumby doesn't get resurrected, - oh PLEEEEEEEZE)
Anyone else noticed anything funny about the elves?
Magic1

I think the elves could apparate and disapparate cuz they worked there and it made the cleaning, travelling and doing things easier. And cuz Dumbledore trusted them...like he trusted Snape! (i hate him! )

it says the reason in one of the books or I read it in one of JK Rowling's Interviews... I think it's because they have different magic, so they aren't affected by the spells and other things put on Hogwarts. Or at least, when it comes to apperating.

That sounds a little more rational to me.Because I think that you can't put exeptions in spells.Like this spell turns who ever steals this cookie into a toad,unless it's a girl and is cute.I don't think spells recognize one person's particular feature to distinguish them from another and choose for it'self whom it curses or not.But diferent races and their effects on or by magic is more plausible.Like Hagrid taking all those stunig curses from the Auros in book 5,because his half giant and they are inmune to some magic.Oii,I think I wen't to deep with this but thanks for the info guys!!!!

This is what JK answered when she was asked this question:

"House-elves are different from wizards; they have their own brand of magic, and the ability to appear and disappear within the castle is necessary to them if they are to go about their work unseen, as house-elves traditionally do."