Get the spray tan at Nectar Skin Bar. They use the Chocolate Organic Sunless system, which has a natural-looking color. There is SPF 30 in the formula.
The fact that it is organic means no funky chemicals are seeping into your skin...and isn't the whole reason we spray tan to be healthier? The cocoa beans also have antioxidants.
Try to run into Adrian Avila on your way out, he does the makeup for a lot of celebs at Nectar (like Gabrielle Union and Candace Bushnell) and if you're nice, he might fit you in his WHCD makeup schedule.
Wear loose, dark clothes when you go and shave and exfoliate beforehand.
Nectar Skin Bar is located in Georgetown at 1633 Wisconsin Avenue NW.