Built this little guy for a mate of mine.
The main housing is from a speaker set designed to plug directly into a small MP3 player. The base is a machined aluminium tape head from an old-school VHS player.
As far as behaviour goes, TemPoe tries to align its solar panels with the strongest incoming light to keep its cells charged. The 2 LDR photocouples on the back allow for light tracking, while a single LDR inside the case monitors ambient light levels so TemPoe can 'sleep' if there isn't enough light available. TemPoe also monitors the output voltage of the 2 photovoltaic cells, which is used to determine whether or not to go to sleep.