I guess it is a parallel queue, It saves the trouble to worry about goroutines and channels and synchronizations, encapsulated the logic that talked in http://blog.golang.org/pipelines last part. To make use of that pattern easier.

I have quite a few use cases myself:

1. Say there is a article on the web, that contains dozens of images embed in the html. Which I want to crawl the article, and Also the images, and put the image into S3 for faster serve. I can use the fanout concurrency pattern to put upload all the images simultaneously to S3 to make it faster.

2. Say I have 20 mysql node sharded data, I want to fetch top 50 latest created data from all of them, and sort it to and show it to user after.

it's a small abstraction, but I could see it being useful. My gripe, and I don't know how to say this without people saying I'm whining about generics, is the interface{} return. Such a pain.