Okay, so would this work?

My idea is to use one of these solar cells (
http://futurlec.com/Solar_Cell.shtml), probably the 6 or 9 volt, plug it
into a small buck switching regulator and charge a 100-200mAh Li polymer
cell.

Reasonable?

The idea behind this is to be able to leave the device (guitar tuner) lying
around anywhere and charging it from ambient light. At most, it would get
used for a few minutes, once a day, max. So not much energy drained from th=
e
battery. I'd like to keep the battery floating at 60-70% charge to get the
most shelf life (years) out of it.

For example, I like the 6V 60mA cell on that page. Good size, reasonable
price. The question is, how much voltage and current can I get out of it
under ambient light conditions? For example, a room with the lights on and
possibly some daylight (not direct sunlight) shining on it.

Any other ideas?

I want to make it as easy and thoughtless as possible to charge the device.
Another option may be an inductive ("wireless power") charging mechanism
where you just put it down on a charging pad and it charges through
induction.
--=20
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