Not logging TBs, or moving them along after picking them up: TB/geocoin owners put them out there to move along, not to be held indefinitely by a cacher. The owners want to follow its travels through logging, so please be considerate and log the TB/geocoin within a week and move it ASAP. If you wish to hold it for any period of time, be sure to contact the owner and make sure he/she is agreeable.
You are looking for a bottle cap cache.