What are common approaches to backup solutions in remote data centers?

I am already familiar with general backup principals and have a very good backup strategy for our local data center but am having great difficulty extending it to a remote data center. We currently do a full backup on Friday, differential Mon - Thu, rotate offsite Friday morning ...rinse and repeat week after week. BTW, we use disks and have been very happy with this approach.

• We could buy a large storage server and backup everything to it, but this solution doesn't give you offsite.
• We could encrypt and upload to Amazon or some other online storage but that would take a large amount of time given the data and would be rather expensive paying for the bandwidth leaving the data center and receiving at amazon.
• We could drive to the data center every Friday and continue to rotate disks as we do now. But that just seems old fashion.

What am I missing, are there better options?