Funny thing going on in the marketplace right now: reading for pleasure is on a rapid decline yet the choice of e-reader devices grows weekly. That's good news for those of us not spending out down-time in front of a television, mouth agape -- awkward for manufacturers testing the waters of this unproven niche. LG's showing off its Solar Cell e-Book reader anyway, in a bid to flex its thin-film solar muscle. The prototype features an energy conversion efficiency of about 9.6 percent giving it an extra day's worth of power from that 6-inch TFT-LCD after about four to five hours in the sun. LG is working towards boosting its thin-film solar cell energy conversion efficiency rate to