"Don't charge LiPo cells unattented" is a bit of mysticism to me. If you have a correct charger that cuts off at the right time, it's not needed. Consider that some fancy pieces of computer hardware (such as large DRAM disk caches) have on-board LiPo cells for memory protection, managed by a proper charger, and those computers are stored unattended for months and years in server closets and data centers around the world. (This is a major use case for 18650 size cells and on-PCB holders for those cells)
RC enthusiasts, that use "raw" LiPo cells without designed-in circuitry and with perhaps un-matched chargers, do well to not leave their cells unattended while charging. But charging your cell phone, or laptop, or some other well-designed LiPo powered device is just as safe as a NiCd or Lead-Acid or whatever other battery chemistry you want -- except you get more power for less weight 
If you really worry, use LeFePO4 instead. Almost same energy-per-weight ratio, with much safer battery chemistry. Basically impossible to "charge until they explode."