Since February I've been happily using Tabbloid to receive PDFs of blog posts I want to read on paper (that's what you're getting if you view my shared posts in Google Reader – those are things I've tagged to be delivered to me by Tabbloid). I just ran across FiveFilters.org, which offers an open-source solution you can host yourself to convert RSS feeds to PDF. Nice bonus is a chart comparing FiveFilters.org to four other services, with PDFs you can view to compare the same content across all five.
update: just realized that the author of FiveFilters.org had left me a comment about this site on my original post back in April :-0