PlaylistMAN

Description:I don't know how you listen to music in Winamp, but I usually load a large playlist and just let it play while I work. However, if you double-click a sound file in Windows, or listen to a streaming mp3 from the internet, the file is loaded in Winamp and your position in the playlist is lost. So once that song is over, you have to re-open your playlist and try to find the song to were listening to before. This can become annoying if it happens frequently.

Enter PlaylistMAN. This is a very simple plugin that loads with Winamp and keeps track of your position in the playlist. Here's how to use it:
-Open the playlist you want to normally listen to
-Click the 'Set List' button. This will become the 'default' playlist.
-If you open another file or internet stream and want to go back, Click the 'Back' button and you will be returned to your previous playlist and the song you were listening to within 5 seconds of where it was interrupted.
-Note that if the playlist does not change, or if the new playlist has the same number of tracks as the 'default' list, the back button will do nothing.
-Closing Winamp will automatically close the plugin

I find this pretty useful, and still use it. It's a WA2 plugin, so it works with Winamp 2 and Winamp 5. It has a few bugs, so it's technically a .5 beta version.
Source note: It's actually two projects, an .exe, which is the main program, and a .dll to interface with Winamp.

Version .5 Original release