Even if you're not near an electrical outlet, with Blackburn's Flea USB + Solar Charger Kit you can still recharge your Flea light. The solar panel is capable of fully charging the Flea in 5-6 hours of full sun. It also charges anything else that uses a USB plug. At work, plug the USB charger in to your computer and you can charge the Flea for your ride home.
Blackburn Flea USB + Solar Charger Kit