There does not appear to be any good software to mount an FTP to a local drive letter (see here for details SF Question) so I was thinking why not just write it myself, but I have very little experience dealing with windows (at the programming level) so what would be involved in doing something like this? What needs to be done to get a new "drive" listed under "My Computer"? What needs to be done to then get the contents of the FTP (or other remote resource) listed that "drive"?
My initial thought would be you would need to write a shell extension to be able to show your FTP site, and that it would best be shown as a special folder in Windows Explorer. Your extension would ideally be written in a non-managed language that supported COM (C++, VB 6, etc). It would need to respond to events like:
When you intercept these events you would issue the appropriate FTP command to accomplish the task (use LIST to get the contents of a directory, MKD to create a directory, STOR to upload a file, etc). You would have to take the results of these commands and show them in the folders view and the listview within Windows Explorer, and for that you will likely need to get up close and personal with the Win32 API. For that you can turn to books like Charles Petzold's classic Programming Windows. Also check out this tutorial on writing shell extensions.
It sounds like an interesting project.