Slideshare can now host you MP3 audio files that will play in sync with your PowerPoint (or Keynotes) slides. And uploading MP3 is free.
If you share files via Rapidshare and/or Megaupload, you may find TinyLoad pretty useful.
By increase file upload space to 3 GB, WordPress is sure to win lot of new hearts especially podcasters and pro-photographers. And if you ever exhaust the 3 GB limit, you can purchase additions space via PayPal.
Compare the top file hosting services that are free and offer unlimited storage space.