If you are using AS3 might want to take a look at Bulk-loader . It has a vast array of features including, but not limited to Connection pooling, Unified progress notification. Events for individual items and as groups.
Priority Loading, Stop and resuming individual items as well as in bulk.

I will be using it more extensively for my next project, so i will report on it after that. In the mean time why not give it a try.

Visit Bulk-loader @ Google Code