This is a first public beta of TouchXplorer for Windows Phone 7, please report any bug you may encounter.
Be careful using TouchXplorer, you have a full access to the file system, so deleting or modifying some files may result in unstable or unusable system.
[after Deepshining Windows Phone 7]
Technically I did not hack the OS, I simply used a signed HTC COM library to grant full access, so it will not be blocked upon OS updates, but I don't know if it will run on non-HTC devices, there may be some hardware specific checks. Update: TouchXperience does not seem to work on non-HTC devices, I will look if I can get full access on other devices.
TouchXplorer must be sideloaded on unlocked devices, as this kind of app will never be approved on MarketPlace.
TouchXplorer is similar to Windows Mobile File Explorer (but with a nice Metro look), it supports all standard file operations (open, edit, copy, move, rename, delete, search files) but you can't create/delete/copy folders.
Future version will include network support (accessing files from your personal/pro network) and FTP support (client & server).
Here is a video demo : http://www.youtube.com/watch?v=57XWYlcZxGM
Tip: How to access files copied from your PC using mass storage hack
Go to \My Documents\Zune\Content in TouchXplorer, you should find your files somewhere here renamed by Zune with a short name, as well as all your synced content. Then copy it on a safe place like \My Documents and rename the file with its original extension. Hopefully I will work on a simpler way to do it and without needing any hack.
Tip: How to simply add custom ringtones
Simply copy your WMA files to \My Documents\My Ringtones using TouchXperience. So you can for example add to ringtones your Zune music (located in \My Documents\Zune\Content).