Please can someone help me.

There is website ww.zyb.com to backup your phone book and calender for Free.

But ist asking to download zyb software onto Iphone from apple.com, when u register to this zyb site they will send u link(http://phobos.apple.com/webobjects/m.../viewsoftware?) to ur phone form that u need to download the small software but its located in Apple.com.
Can be jailbroken phones download stuff from apple.com
Can i download from think onto my iphone without locking it again.(wants keep unlocked)