is there a way to enter the same song into two playlists and NOT have it take up double the disk space?

This is discussed in excruciating detail in The FAQ. Read it. Learn it. Live it.

Regarding M3U imports... There will be some M3U functionality in 1.1 as I recall, but I can't check it right now as I'm running 1.03 for a while in preparation for its release.

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Tony Fabris