It was about 36 hours ago that I pointed to a ResourceShelf overview of Writely, a wonderful and free web-based word proccessor and collaboration tool. Today, according to this article, Writely has added a new feature. Now users can convert documents into PDF format by just pointing and clicking. The article says that this is now free feature will eventually become a "fee-based" premium feature from Writely.
More in the article: Web word processor adds PDF conversion.
Of course, many other web-based convert to PDF tools exist. Here's one example. For years, I've been using DocMorph from NLM's (National Library of Medicine) Lister Hill National Center for Biomedical Communications.
DocMorph has been around since 1999. It's a completely free service that allows conversion to PDF, TIFF, text, and synthesized speech from more than 50 file formats. Registration is fast and easy. You can also download (not required, Windows only) MyMorph that makes the conversion process a bit easier (it's really not a challenge in the first place).