>     What's your favorite opto-transistor?  I need to be able to "see"
>     sunlight with an opto-transistor (no accuracy required, using an
>     infrared transistor seems fine).

Look at the TI light to frequency converter. Comes in a transparent
8pin DIP. Generates a pulse train whose frequency depends on
the light on the package. I just read about it in the Nov Nuts &
Volts (recommended BTW, info at http://www.nutsvolts.com/). Part
number is downstairs but I'm sure TI's web page search would find it.

Worth it to have a transparent IC on your board :-) :-)