Bloglines (excellent web-based RSS aggregator) has a mobile version (
http://www.bloglines.com/mobile) but it's designed more for connected (eg wireless) PDAs than for iSilo use.
I have suggested to them that they should support iSilo for offline reading. They liked the idea and were going to add it to the to-do list. I mentioned also the issues with read vs. unread articles - downloading all your unread articles to iSilo should not (IMHO) result in these articles being marked as read on the server. YOpinionMV of course...