Podcasters and pretty much anyone in need of low-cost (as in free) audio editing software have been using Audacity for years. It's not quite as full-featured as Pro Tools or Adobe Audition, but with each release, Audacity becomes a more viable alternative for music producers, podcasters, and radio journalists.

While the last stable release of the cross-platform audio editor was version 1.2.6, the developers recently pushed out Audacity 1.3.3 beta, and it's miles ahead of the stable version. Here are just a few of the latest updates:

• Import Quicktime files in OSX (mov, aac, m4a)
• Add metadata to OGG files
• Improved export option selection
• EQ and effects improvements
  
• Screen capture utility
• Improved spectrogram rendering
• Selection bar improvements
• New features for label tracks
• Auto-save and crash recovery
• Collapse and expand tracks
• Multiple clips per track

But if you're looking for a more traditional audio editor, you might want to check out Reaper. This audio editor from Winamp creator Justin Frankel is under constant development, but it's already a full fledged program. And best of all, it's uncrippled shareware. The full license is $40, but you can use it for free for 30 days. And at the end of the trial period, you can continue to use the program, but it will nag you until you register.