I checked some dictionaries and found out the following words to be used for objects whose names are forgotten:
whatsis, whatchamacallit, thingummy, dohickey, dojigger, doodad, doohickey, hickey, gizmo, gismo, gubbins, thingamabob, thingumabob, thingmabob, thingamajig, thingumajig, thingmajig.
Which of these words are really used in colloquial cases? What colloquial word do native English speakers use when they don't remember a word at that moment but they still want to use a word instead of it?