The PDF Browser Plug-In plugs a long-standing hole in the OS X experience, and does exactly what the name suggests - with it, you can view PDFs in your browser. I see a minor cosmetic issue with it, but I'm very happy to have it. Forget Pick of the Week; nominate Manfred Schubert for beatification.
[Editor's note: Not much more to be said; if you'd like to read a PDF in your browser window without downloading and switching to another application, grab this plug-in! I tested it with Chimera, and it worked fine...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20021115061051935