I first saw MollaSpace's Pulpop MP3 Speaker at the NY Gift Fair and was pleasantly surprised by this donut-shaped recycled pulp device’s loudness (5 watt R.M.S.). The sound is simply amplified by the vibrations inside the hollow space.
The speaker is rechargeable via USB and although this might be very practical, it would be environmentally friendlier without the battery. Nevertheless, Pulpop is very lightweight, and although a bit bulky during transportation (10.2 x 11.6 x 2.4"), a very cool object that fits into any interior and is made from not much more than paper. Pulpop is available directly from MollaSpace in white and brown for $56.