Feedbooks is providing a similar service. The only difference is that they -only- convert the RSS Feed of a website into a pdf document that can be downloaded without costs from their website. The whole process is as simple as it can get, paste a feed into the form, hit submit and download the pdf document at the end.

Feedbook provides A4 pdf downloads, Cybook & Sony Reader, iLiad (whatever that is) and custom documents. I was not able to explore the custom option further because one has to signup to create those.

Feedbooks provides a button that webmasters can embed on their website. I have not tried it yet but I guess it would be possible to use one of the many feed combination services to combine many feeds into one and paste that url into Feedbooks to create a huge pdf document from multiple feeds.

Feedbooks offers more than just this RSS to PDF service. Users can download e-books as well that can be sorted in various ways. I encountered some error messages from time to time when I tried to convert some feeds.