The mp3 player I have works by drag and drop, I got this as it would fully support linux without any problems.

And it does- however;

Whenever I add new music to the HD on my computer, I have to manualy drag and drop it into the appropriate folder on my player. If I do not remember exactly what songs I added, then I have to transfur my entire collection onto the mp3 player again.

So what I'm asking for is a program/script that will keep my two music directories identical, only adding the files that need to be added. Apple's Itunes does exactly this, however it only runs on windows.

Thanks in Advance

check man rsync

And amarok can also do syncing (with a nice GUI)

For graphical gui tools, the kde program, krusader, can also do that quite well and many other things.