I am increasing the capacity of our server from 40GB to 120GB. This puts backup's beyond our current 40/80GB DLT drive. I have looked into SDLT & AIT with capacities of 100GB+ but these seem very expensive.
I do full backups Mon/Wed & Tue/Thurs and take a backup off site on a 4 week rotation.
Backing up data files (CAD, Photoshop, Word, Excell etc) & Email (Exchange Server)