Is there any hard drive which can be controlled by two different interfaces at the same time? E.g. two USB ports, or one USB and one SATA, or one USB and one LAN/NAS?
No common OS expects data on a disk to change by itself. Such a device wouldn't be considered a disk and couldn't be used just as one. It'd have horrible performance, wouldn't be safe (OS access controls can't be enforced) and wouldn't be cheap.
Try defining your use case and asking what hardware/software could do it. You may get better possibilities this way.
Actually, contrary to common sense expectations there is such a thing: Multipath I/O - devices with several connection routes to the system (which communicates with such a device). Such redundancy is typically a requirement of a carrier-grade systems. Often the device is within a SAN with iSCSI or FC being used as interconnect.