In an nutshell: We write all BAK and TRN backup files to a specific folder (DB_BACKUPS) on each database server. Several times a day (depending on the frequency of BAK or TRN writes) a centralized server "picks up" the contents of the "DB_BACKUPS" folder and writes the contents to a Virtual Tape Library (VTL). VTL contents are then written to Tape and are held off site. We have a 2 day retention of backups on local severs, roughly 7 days retention at the VTL and (in theory) limitless on Tape.

Happy T-SQLing