Peter Forret has developed a collection of useful online tools for podcasters.
Podcast Feed Validator automatically checks for RSS feed validity, enclosure validity and the availability of the audio files.
Podcast Icons for your audio or video podcast, based on the Firefox icon and adopted by Microsoft for IE 7.0.
Podcast Media Player lets you stream an MP3 audio file using WinAmp, iTunes, Windows Media Player, RealPlayer, SMIL player.
You can find more of Peter’s online tools at http://www.forret.com/tools/ including the excellent Webjay Wizard that lets you easily create an embedded media player for websites.