If you received, and read, your Groundspeak Weekly Newsletter this week, then you learned that you can now mark trackable items as missing - a feature, in my opinion, that is long overdue. Geocaching.com now gives both trackable item owners and cache owners the ability to remove trackable items from the cache listing right from the trackable item's details page:
Instructions on how to do this can be found in the Groundspeak Knowledge Book. Once you select "Go", it will show the Travel Bug or Geocoin as being recently spotted in an "Unknown Location":
Later, if the Travel Bug is found elsewhere, it can be grabbed by the geocacher and placed in the correct location.
This is a nice feature, and I'm glad to see it is available.