I would suggest visiting EcoModder's "Alternative Transportation" forum for more in-depth coverage. Here is a thread we were discussing just this week!
http://ecomodder.com/forum/showthrea...ike-31669.html
You might want to peruse these as well, as they're more focused:
IHPVA - International Human Powered Vehicle Association
It's mostly recumbent-oriented but you do see a few articles about streamlining diamond frame bikes. The first issue has a lot of DF pictures.
Another great resource is
Recumbents.com, and although it is dedicated to bents, you will be able to adapt many of the design and construction techniques to a diamond frame.
Much like ecomodders, the HPV crowd loves coroplast and boat tails, so you'll probably fit right in.
PS- It should be noted that there is a lot of money-grabbing club-racing nonsense in the Bicycle Industry, but I've found the grassroots HPV racers to be much more honest about what actually works. If you look up the UCI ban on recumbents in 1934, you'll see why the conventional bike industry mostly avoids the "low hanging fruit" aeromods. This makes it more difficult for the average Joe to optimize his non-racing performance.