After a bit of a hiatus, CeRegEdit, a free Pocket PC registry viewer that runs on a Windows PC has been updated to include background loading of the registry (via ActiveSync) and a search capability.
As the website, says, "Although it's called CeRegEdit, it's just a viewer right now. Please try it out and let me know what you think should be added. Most obvious is making it into an editor."
--Terry Westley