I read something on the hour of devine mercy... it almost sounds as though it can replace confession. is that true? it seems kind of like a copout...but if it doenst replace confession than what exactly is it all about?The Divine Mercy devotion is not meant to replace the Sacrament of Confession. There is an indulgence attached to the recitation of the Divine Mercy chaplet, but indulgences don't effect the forgiveness of sin, instead they remit the temporal punishment of sin.
The Lord also promises that, through praying the chaplet during the hour of divine mercy (3:00 pm), He will "refuse nothing to the soul that makes a request of Me in virtue of My Passion (Diary 1320)." But, this is not meant to exclude the Sacrament either. Perhaps it is presumed that the person who makes a request of the Lord during this hour would already be in right relationship with the Lord, or that such a person would not ask the Lord to circumvent the Sacrament to begin with. Of course, the Lord is not bound by the Sacraments and He can surely do what He wishes, but normatively speaking, the Sacrament of Confession is the instrument for the forgiveness of mortal sin.
The Divine Mercy Chaplet is not meant to be trickery or a cop-out of the sacramental life. Its purpose is to cultivate trust in the Mercy of the Lord, and mercy towards our neighbor. When we honor him with our lips, we want him to find a heart that is close to him, and this devotion aids in that. It is a wonderful and beautiful, yet also very simple devotion.
"For the sake of His sorrowful Passion, have mercy on us and on the whole world."
For more information on the Divine Mercy devotion revealed to St. Faustina, go here and here.