  The acceleration of a jet to relativistic velocities produces a unique memory
type gravitational waves (GW) signal: {\it Jet-GW}. I discuss here resent
result concerning properties of these GWs and consider their detectability in
current and proposed detectors. Classical sources are long and short Gamma-ray
bursts as well as hidden jets in core-collapse supernovae. Detection of jet-GWs
from these sources will require detectors, such as the proposed BBO, DECIGO and
lunar based detectors, that will operate in the deciHz band. The current LVK
detectors could detect jet-GWs from a Galactic SGR flare if it is sufficiently
asymmetric. Once detected these signals could reveal information concerning jet
acceleration and collimation that cannot be explored otherwise.
