Software to organize your personal music collection is really evolving fast.
There are more features being packed in.
Not just playing a mp3, now you can even burn CDs or create labels for CDs, which was once possible only from CD creator software's.
Updating MP3 tags or grouping the files based on the tags is feature I find most useful.
Who wouldn't like one software to do everything, atleast most related ones.
You can group songs by Album/Artist/Location/Genre and so on.
And as, MP3 tags allow upto three comment tags, you can add your own comment and device your own classification system.
Take a look at the image here.
I have used the 'Genre' tag to record the Raga of the song. Raga in Indian Music system identifies the scale of the composition (well, its much more than that, but a shorter version will do here).
I have used a software from JRiver called 'MediaJukeBox', there are many more software's available, being released and upgraded everyday.
Microsoft's Windows Media Player does include some of these features in Ver 10, but that's available only in XP. But I wouldn't depend on Microsoft.
Update on Mar 07, 2005
Now, in XP, Windows Explorer itself displays the MP3 tags, so you can sort and group by the MP3 tags, but doesn't let you edit the tags.