Concurrent Downloads using NSOperationQueues (eng.alphonsolabs.com)

Nice tutorial summarizing this useful action. The ASIHTTPRequest lib is also good to note here as the ASINetworkQueue NSOperationQueue subclass allows for tracking progress of the entire queue in addition to a few other useful delegate methods

http://allseeing-i.com/ASIHTTPRequest/How-to-use#about_ASINe...

This page doesn't mention it, but it's interesting to note that the NSOperation subclass used here actually does all of its work on the main thread.

Here's an example of the kind of speedup you can see from proper usage of NSOperationQueues: http://tech.gilt.com/post/3187131303/tips-for-optimizing-iph...

Pretty impressive to see them running side by side.