After some prodding from customers and an upcoming prototype run I decided to throw in a little breakout board that would allow 2 solar panels to be connected in parallel to a 7805 linear regulator. An LED was added with a switch so the user could identify when the board was making power. These boards can output 8V@300 mA and should easily provide more than enough votage and current to charge the batteries. This setup is perfect for backpackers and other users looking to ditch their backup AA batteries.
Only indoor testing has been conducted on these (its nightime right now) but some 23W florescent bulbs provided enough voltage to light the LED charging light of the gps logger!