Digg’s shout system is currently flawed. Spamming through the shout system is simple, while sending messages to all of your friends is difficult and time consuming.
Here’s an idea that might just work: using a well recognized od digg as a code to let your friends know that what you’re sending isn’t spam. Currently, many users, especially those with lots of friends, have a hard time because of the sheer bulk of shout spam that they receive on a daily, sometimes hourly, basis.
This is an idea that could fix the system until Digg steps up and fixes it themselves.
But if instead of Digg, you need VC money: