Experimental work on cold, trapped metastable noble gases is reviewed. The aspects which distinguish work with these atoms from the large body of work on cold, trapped atoms in general is emphasized. These aspects include detection techniques and collision processes unique to metastable atoms. Several experiments exploiting these unique features in fields including atom optics and statistical physics are described. Precision measurements on these atoms including fine structure splittings, isotope shifts, and atomic lifetimes are also discussed. © 2012 American Physical Society.