Google provides an ImageLoader library. It kinda sucks, and occasionally causes Application Not Responding errors or out-f-memory exceptions in my company's apps, but there's nothing better that's open-source. I wrote something pretty cool at my previous job that unfortunately probably will never be open-sourced that pipelined and cached image fetching, and supported a responder-chain like pattern for handling the images, as well as decoding it to a limited size rather than fully decoding into a full-sized bitmap and then resizing, as that would occasionally fail due to the bitmap decoder deciding to return null sometimes - probably in low-memory cases.
For our most recent project, we took GreenDroid and extracted its AsyncImageView stuff, removed or changed GD dependencies, and changed to a SD file based cache. The GreenDroid open source code supports many of the concepts you mentioned, including the responder chain.
The SKImageDecoder returning null is a pain.
Thanks for your reply. Check out http://droidux.com (just saw a tweet about it)