Here are two little fimo keychains I made for my friends. First up, for a Doctor Who fan, a TARDIS pendant. I used scrap clay for it, then painted and varnished it. That's why it's so shiny. Too much varnish ;-)
Your basic polymer clay cake. No varnish here.
And a simple coffee cup. It took me ages to shape it, and it still doesn't look like I wanted it. It's about the size of a coin.