iPhone offline client

Thanks to Instapaper, and more recently LaterLoop, I've shifted much of my longer-form online reading to my iPhone. It is fantastic for all manner of reasons. However, there are times when offline access (and even just faster, cached reading through multiple items) is indispensable. Instapaper has gone after this with an iPhone app, which, while buggy, is a great start. Through it, I was able to read a number of long pieces still in my queue while on airplanes this week. Other than this one feature, I prefer LaterLoop, and have long since switched to it exclusively (thanks largely to the great import features).

I would love to see LaterLoop also offer an offline reading client, or even an API for getting at the service in writing my *own* offline client.