Question: All of the ones I can think of are specific products that have come to represent their kind. This is usually either because it is the first of its kind, as in a Xerox machine (the first office photocopier), or it arises from popularity, as in Sharpie or something like "Google that" (though I'd say that's a bit informal/debatable).

Other examples I can think of off the top of my head are:

* Kleenex
* Post-it

Answer: 
* iPod (I've seen many people use iPod to refer to any MP3 player)
* Xerox
* Zip-lock
Left out *Jacuzzi* - the generic term is *hot tub*; and perhaps *fridge*, which according to [the Online Etymological Dictionary](http://www.etymonline.com/index.php?allowed_in_frame=0&search=fridge&searchmode=none) is:

> 
> shortened and altered form of refrigerator, 1926, perhaps influenced
>  by Frigidaire (1919), a popular early brand name of the appliances.
> 
> 
>