Well, it would be possible to restore a file on a Storage Card if you have an adaptor for your PC. You should then be able to use PC tools of the types you mentioned against the storage card. The chance of restoring a deleted file is extremely good, if you haven't placed additional files on the card after the delete. Writing to existing files on the card could also destroy the deleted file if the files being written to grew in size.
Regarding deleted files on your Pocket PC's internal memory; a Pocket PC program would have to be written to attempt such a recovery. I don't know that the OS would allow low-level access to that memory as is possible with Storage Cards, because that storage memory is very "abnormal". First off, all files stored directly in your Pocket PC RAM are compressed by the OS. So right there is the first major problem. The second is that the RAM is shared between Storage Memory / Program Memory, so I don't know how those dynamics would affect such a recovery. The more I think about it, I doubt the internal Storage Area even uses a standard File System like FAT. Some sort of automatic defragmentation would have to occur on the fly, so all the files are continuous in RAM so the rest of the RAM can be used for Program Memory. So I said all that to say that I really doubt any tool could even be written to recover deleted files from internal Storage Ram.
Dan East