"Clip Converter is a free online media conversion application, which allows you to convert and download YouTube URLs to formats like MP3,MP4,AAC,3GP." This is a great resource for saving videos for offline viewing as well as converting media to viewable formats.
Online Art Exhibits from the Library Company of Philadelphia includes historic documents, photography, broadsides, paintings, and other ephemera. It's definitely worth having a look around if you can't go in person.
"Floola is a freeware application to efficiently manage your iPod or your Motorola mobile phone (any model supporting iTunes except iPhone, iPod touch and nano 6G). Floola Desktop is another freeware application to manage your local PC music library. Both are standalone applications that do not need installation and run underLinux (any GTK2 distro), Mac OS X (10.4 or newer!)" --I have used Floola to retrieve music files off of an old ipod that itunes would not allow me to use the music from. If anyone else has had this frustrating problem, Floola is your friend. It also allows you to use your ipod like an external hard drive and drag and drop files to and from it...no syncing necessary.
Internet Archive is a non-profit digital library. You can download books, movies, music in the file type/format of your choosing for free. They have lots of out of print or otherwise unavailable materials.
Audacity is a multi-track audio editor and recorder in the same vein as pro-tools, but free to use for Windows, Mac, Linux. Music tracks can be edited individually, mixed and exported in multiple file types.