Product review (4 stars): NewAir Portable Countertop Icemaker (black)
I picked up one of these ice makers because I was tired of messing with the ice cube trays that had taken over my freezer.  We use a LOT of ice in the summer, and it was getting to the point where we were running out of fully frozen ice cube trays by mid-afternoon.  I run the ice maker twice a week, bag the ice in 1 quart freezer bags, and pile them up on a shelf in the freezer.  When I want ice, I thunk a bag on the counter to break it up, and fill a glass.

The machine *does* have a fan on the side to vent the hot air produced by the compressor, and it does make my kitchen a bit warmer--particularly when the temperature outside is in the 90s.  However, it is not terribly noisy, and it doesn't create any unpleasant vibration on the countertop.  It lets you choose from three sizes of ice--S,M,L.  The size difference is actually in the thickness of the ice, which forms on condenser "fingers" in the top, back portion of the machine.  The larger the size, the thicker the ice that's allowed to form on the fingers.  The ice itself is not a cube, but a bullet-shaped tube of ice, like the bottom of a test-tube, with an opening on one end.

The small and medium sizes are a waste if you're pouring hot liquid onto them--they disappear immediately.  The large size is the best if you need it to stand up to freshly-brewed tea and coffee.  For beverages that are already cold, the smaller sizes seem to work well enough.

So far, I like the unit, I like the look of it on the counter (next to a black countertop convection oven), and I haven't run out of ice.  :)