I use it on every phone handset at work... I guess it's the switch PoE not the pc mobo but the effect is the same.
If you are talking pc mobo PoE I guess it could be handy if you had a PoE camera...
In the garage is fine, but this is about inputs and outputs. Electricity entering or leaving a house via a garage (or front door), and not via power lines, generally indicates something is very wrong. That's quite a large air gap to cross after all.