• On standard tapes or micro cassettes
  
• In digital file formats such as .WAV, MP3, .WMA and others.
  
• DVDs or audio CD's (special software "rips" the sound off these into an MP3 file)
  
• A variety of media cards such as Sony Memory Stick, MultiMedia Card, SmartMedia, etc.

For transmission of digital files over the Web,
I recommend a free service called www.sendthisfile.com. Your files go to their server, and I get an e-mail with the link to download them. There are also other free services, such as Pando and www.yousendit.com.

Your transcript will be e-mailed back to you once it's finished, and any tape/CD/DVD returned by regular mail.