Here's one, cheap but not very good performance.
# Solar energy board: 5.5V/80mA 200 mAh built-in Li-polymer battery 5.5V and 1000mA output
# Direct sunlight charging time: 10 to 15 hours
# AC adapter charging time: 5 hours
# USB link to a PC changing time: 5 hours
# 60-minute recharge gives the mobile phone an additional 100 to 150 minutes talk time
# Compatible with: mobile phones, PDAs, digital cameras, MP3 and MP4 players (battery capacity must be under 1200mAh)
So would that model work? Well yes, but in DIRECT Arizona sunlight you would get LESS capacity than with a normal battery.
80ma charging power is next to nothing. Most USB ports charge at 500ma, and some charge at upwards of 1000ma (1A)