Universal Flash Question
There's a chance that Quantum will.
Their radio system can be used with Nikon and Canon quite easily, and I've heard that they updated a Nikon adapter to work with Olympus. They currently support a range of Pentax cameras, but the K5 doesn't seem to be amongst them. Ask Quantum. One set of flash units would only need an appropriate TTL adapter for each camera.
|Valley by the light of a blue moon by cjf2|
from Down in the Valley
|Lake Erie Stone Pier by yobbyt|
from Dock or Pier
|Hong Kong by Zephyr1977|