RSS readers are better than obsessively checking 18 or so web sites myself, but they seem to share one very annoying feature. They assume I read news/rss on only one machine, and I have to manually mark off which articles I have already read on a different machine.
Similarly, nntp readers (that I know about) have only a local idea of what is read and not read. For me, this makes reading high volume lists via gmane almost unbearable.
Am I the only one that wastes time on more than one computer?