Patent Retriever is a new service for downloading patent documents. Launched just days ago (May 30), it will retrieve US, EP and WO (PCT) patent documents in PDF format fairly quickly, although I haven't timed it against other similar services. Users may download single documents or up to ten documents in batch download mode. It appears to retrieve some US documents from the EPO's esp@cenet database and some from the USPTO website. However, it does not appear to retrieve pre-1836 patents (X patents) or additional improvement patents.
I'm the librarian for research services in the Engineering and Science Library at Queen's University in Kingston, Ontario. I've been working with patent information since 1991, including seven years at the U.S. Patent and Trademark Office. I believe that the dissemination of patent information is a public good and should be promoted, especially in the education of science and engineering students.