(See the Bento Decoration master page for my general thinking on decorations.)
Japanese people love wiener sausages. They appear quite often in home cooking recipes. Wieners are the Play Doh of the bento making world since they are colorful and easy to manipulate.
I don't like to use wieners their relatives very often, though living in a Germanic area of Europe we can get pretty good ones that aren't dyed a bright pink and actually contain real meat. But once in a while they do appear in my bentos.