It really depends on how often you do your hot backups. You need all of your archive logs from the beginning of your last hot backup (plus the hot backup files) to be able to do a full recovery. If you want to be able to recover to a previous hot backup then you need the archive logs from the beginning of that backup.
But you can save them offline (on tape or cd) as long as you don't mind the extra time needed during recovery.
If you can move them elsewhere on your harddrive then that is probably best.
HTH,
Paul
