We can't tell you how often we've had trouble finding an address because we can't see the house (or business) numbers. SF-based design company matterinc has come up with one solution to the problem. Made of anodized aluminum, the Solar LED Numbers are weather-resistant. They project 1" from the mounting surface so that the LEDs illuminate the background and reveal the number. The light lasts between 8 and 10 hours on a bright sunny charge (we wonder how they do in fog? *see update below the jump*).
The numbers look as though they'd also be easy to see in the daytime. Available in silver or black, for $19.99, here. Rainy Day Magazine has step-by-step installation instructions with photos, and a glowing review. Maybe we should add these to our Top 10: House Numbers. Update: Edmond from matterinc says: Our LED's only require about 1 hour of direct sunlight to fully charge the AAA Ni MH battery. On cloudy and foggy days it will simply take longer to charge thoughout the day but it will be fully charged in 3 to 5 hours in ambient or indirect lighting. The AAA battery will last for 3 to 5 years but it is in a battery holder so you can replace them at anytime.