I would like to write an application that will copy MP3 files to a SanDisk Sansa M240. The SanDisk doesn't have a drive letter and uses MTP for file transfer. I stumbled through the sample of connecting to the device at : http://blogs.msdn.com/dimeby8/archive/2006/09/27/774259.aspx
but once connected, I can't figure out how to actually copy files / create folders on the device.
I am very surprised that there aren't any .Net wrappers for this COM library.
It looks like dimeby8 posted some code that handles data transfers. Check other posts in his blog, especially:
Sending MTP commands through WPD part 1