bacterial flagellum constitute a kind of natural nano-sized 'motor' complete with armature, stators, and bearings. Truly amazing and on the sub-cellular level.
Flagellar Whip Section (Scanning EM)
Flagellar Cap
Flagellar Cap (cont'd)
And believe it or not, there is something even more spectacular that the bacterial flagellum! For more, see the following:
http://creationontheweb.com/images/pdfs/tj/j21_2/j21_2_109-115.pdf