Scribd offers a mobile reading option. And (shock) it incorporates Facebook/Twitter feeds.

From the Department of Emerging Digital Reading Practices…

If you like the idea of Instapaper (which I do!), but you tend to forego RSS feeds for Facebook and Twitter, then Float from Scribd might be just what you’re looking for. Stories from people you follow. On your phone. In reader-friendly, stripped-down typography. The video is pretty much spot-“on in terms of function/use. I love it. Give it a try.

If you’re already happy with your own portable reader, point us to it. Let us know why you like it so much! Otherwise, give Float a shot and help support Scribd, one of the great document-distribution sites on the Web.