Are you a DJ or just want to create a cool mix for your next party? You can do it with Acoustica MP3 Audio Mixer. Add as many files as you want, drag-and-drop them and save them in mp3, wav or wma format. The application supports wav, mp3, mp2, mp1, wma, cbs, m3u, pls file inputs as wel as its own input/output format: sgp.
Pluses: Complete control over volume, pan and playback, easy to use interface.
Drawbacks / flaws: It only does what it's title says. In case you need more than mixing audio files, you need to look out for some other applications.
In conclusion: An easy and relaxing mixing tool suitable for beginners, DJs, radio people and basically for anyone who wishes to juggle with audio media.
