Pretty much all the hologram based ideas are pretty ace and doable with modern CGI and a half decent budget (should they make a new series). They are also logical tech steps. My idea was a more basic safety device, probably not realy utilised unless there was an emergency. It's basicly a small (half the size of a modern phone maybe) device that activates automatically should the wearer be exposed to a vacuum. When activated a spherical forcefield would be erected and breathable atmosphere injected into it. This would only be a temporary measure to help keep 'ejected' crew members alive long enough to be transported/tractor beamed to safety. The device could also be equipped with a homing device to facilitate a speedy recovery and a 'euthanise' button. This could be used if you realise help is not on the way and the power on the device is running out. Power would run after a short period of time. Either way it would beat being having your blood boil.