The 2006 HCH 2 comes standard with full front seat airbag protection(side and side curtain and frontal airbags) and side curtain bags that extend to protect the heads of rear passengers. Same story for the HH and the Accord.
You can get full airbag pks as options on the other new Hybrids.
Luck,
Charlie
PS It is pretty CS for Toyota to sell a tiny car like the Prius-for >$25000+-and to not have side/side curtain airbags standard.Instead they push useless,but very high profit margin crap like Nav etc.