And it's just not 's, it's contractions too that don't work in the label/tag cloud widget

So no "can't" in the labels. And no "don't" or "didn't" either. And forget about "huntin'" and "fishin," although I would probably not use those as labels.

However, this goes against the basic idea of folksonomies.

See Daniel Pink's New York Times article for more information on folksonomy.