From what experience I have had of the East:
While I absolutely concur with what others here have said, I would also like to add that there is a difference in the way penance (and indeed, the whole of penitential spirituality) is lived out. Within the West, there is much more of a tendancy to view and explain things in juridical terms. One accuses themselves of sins committed and God, acting through the priest, pronounces forgiveness and administers a sentence (penance) that must be carried out in order to expiate the temporal consequences of sin.
Whereas in the East, there is a tendancy more to view and explain things in a more healing, medicinal terms. One confesses the wounds which have been self-inflicted (sin) and God, through the priest, pronounces absolution. However, the penance is more thought of as a medicine; something that is done to help cure and (hopefully) prevent a relapse into sin (particaularly if a penance is assigned especially for a specifc sin).
Of course, this is not to say that there is no knowledge of medicinal language in the West and juridical language in the East; rather, these are things that I have picked up on in my small experience. If I have mispoken, please correct me.
On a related note- I agree with what has been spoken of here and elsewhere. Alex, your responses are so knowledgable and deep. For these, and your friendly tone, I salute you