Becky Harris Hmmm, this good be a good ideabook topic, perhaps for our architecture experts...I've also seen some rain chains looking really cool on contemporary houses lately. Erin Lang Norris featured some of those here:

Sheila Schmitz Also some good ideas for contemporary gutter designs in this story about downspouts by Houzz contributor John Hill:

Mathew Amaro Designs Flat roofs such as this sometimes don't use gutters. Water is diverted to drains much like a floor drain
with the use of built-up material under the roofing which may be a single ply membrane. The downspouts many times are also hidden in the walls. All of this adds to the clean horizontal lines common in mid century modern style of architecture.

Huy Ho Flat roofs may drain through the soffits, or walls which is troublesome if repairs are requied. Also depending on climate, you want the downspout exposed to the sun so it wont freeze up. Commonly flatroofs will drain from a scupper of the side. There are only a few profiles to choose from but if curvy is your thing, use k-style. If you are more of a square, use NS-style. Minimum 5" but 6" is better