iTunes is a great piece of free software. It is designed to work with iPods, but you can use it to organize your music or other audio files.
You can also use it to access thousands of audio files that are free. Podcasts of all types and qualities are available, and they even have a section for educational podcasts.
Apple makes great computers, and Steve Jobs is started three technological revolutions. The fist was to make a desktop personal computer. The second was to make a portable digital music player, and the third was to make a portable computer that fits in your hand (iPhone). Each revolution has changed its respecitive industry (computers, music, phones).
The iPod is a great tool for education. You can load audio, and even video on to an iPod and it becomes a portable media machine. It works better than a CD, cassette or MD player. You can bookmark places in your sound files to go back to the exact place each time. Get the AV cable to connect to speakers and digital projectors.
I really like this directory of web 2.0 sites for the variety of names and logos that have proliferated (spread) in the last few years. It is much easier to make a web 2.0 site, it only costs, on average, about $100,000, where in the year 200 Internet bubble the average cost for a site was about $1,000,000. These sites all have a few things in common: they are simple, they do one thing and do it well, and they are almost all free. Explore, enjoy, spend some time. Or look of a specific kind of site, as well. Go2web2.0.
With Gmail, or Yahoo Mail, you can send files up to 10 MB, which is pretty large (a 10-minute mp3 file, for example).
But sometimes, you need to send someone a file that is larger. My favorite service is YouSendIt. I send files to Boston and get them back fine with this service. Normally, a geek like me would use FTP, but that requires owning a web site and using specialized software. With YouSendIt, it is all done on the web, and is very similar to sending an email.
Sometimes you have a DVD with a small section of video you want to use in class, or want to put on your iPod, or you want to edit a little for your class use. This is legally OK because it is called Fair Use, an exception to copyright, specifically for education. HandBrake is a software you download and install on your computer to change from one format to another.There are many different video formats, and not all people can play all the formats on their computers, so a coversion software is necessary. This one is free, and works very well. This does require some knowledge of editing videos to use well. Sorry, no Japanese version available.