If you put your itunes library on a memory stick but add to the library on the PC, can you add the extra tunes to the memory stick or do you have to wipe it all off and start again?
If it's just your iTunes folder, then you'd either copy the entire folder and say No to copying and replacing the existing files (To speed up the operation), or just copy `n' paste new albums as they are added. Assuming that you're running iTunes off the PC and not the Memory Stick.
I can't see that you'd wipe the memory stick and start again.