UPDATED: Trackographer v2.0
Trackographer v2.0 is a stay-open applet that will monitor iTunes as tracks are playing and send tag information from each playing track (including radio streams if they provide track info) to a text file. Preferences can be set to include or not include various basic tags and to create a plain text file or a tab-delimited text file which can be imported into a spreadsheet. The text output looks something like this:
This latest version is a maintenance update that fixes some issues with text not rendering properly in modern OS's.