Better portable power sources are always on the wish list. Many, many electrical gadgets could be shrunk even further if it wasn't for the bulkiness of batteries.
That might technically relieve the "bulk" problem, but only by substituting a "surface area" problem in many cases.
Better solar cells are also on the eternal wish list, though. Not that they haven't been slowly improving, and not that they aren't already good enough for many things.
I thought I remembered reading about a new LCD touchscreen, coming to an iPod/iPhone soon perhaps, which is also a solar cell... That would simply rock.
