It's leaner, it's meaner, it's Nitro PDF Reader. Available in 32-bit and 64-bit editions, new version 2 of the PDF viewer/creator/editor whose interface mimics Microsoft Office's to a great extent (2007 and now 2010--a good thing in my book), is now noticeably faster both opening and saving PDFs. This is no mean feat, as it was very fast before. Its new browser integration is nice as well.
Nitro PDF Reader was never just a reader. It installs a driver that turns any kind of document into a PDF by simply printing it, and it's one of a handful of free tools that allows you to add your own text to any kind of PDF. This ability means you can fill in PDF forms whether they have editable fields or not. It also has the ability to extract both text and graphics as well as embed a graphic of your signature. The latter task is now called QuickSign, but it appears procedurally identical to the old process: Load a picture of your signature, drag it and place it on the document, then double-click it to embed it. The program also installs it.
Probably the best new trick is integration with Web browsers. Nitro PDF Reader will open files in both IE and FireFox so you don't have to open a separate viewer. Unfortunately, there doesn't seem to be any way to change the magnification but it's still handy. Nitro PDF claims that the files it saves are now smaller; however, opening then resaving a couple of book files resulted in the same size file from both versions 1.4 and 2.0. This was hardly a thorough test, though, and your mileage may vary.
I hate to complain about a free tool in any fashion. However, I have a wish for the list--that the program would save files in ebook format. Adobe Reader on Windows Phone 7 isn't all that configurable, so I like to turn some PDF books into .epub format.
Despite my nitpicking, Nitro PDF Reader is easily the fastest PDF viewer and the best free editor around. It's a must-download for anyone who deals with PDFs. For me, it has replaced the Foxit 2.3/BioPDF reading/creating combo I used for several years.