Is there an easy way to get a list of all my songs in iTunes into a text file?
This is actually insanely simple:
Open iTunes and go into your music library. Click on a song to ensure focus is inside the song list, press ⌘a to select all your songs, then press ⌘c to copy them.
Open the text editor of your choice, anything should do, then ⌘v paste your songs!
Ét Voíla, all your songs listed in plain text.
You can get a nice pdf with the content of your music library: hit
⌘P to open the print dialog, select "Album list" (I'm using a not english version of iTunes, son I'm not fully sure of the label, I mean the third radiobox from the top) and the "Only text" theme (the first option on the select field). Click "Print..." and then Save as PDF.
The resulting document is really nice:
You already have one - albeit an XML file. Default place is ~/Music/iTunes/iTunes Music Library.xml