jEmplode will upload everything. Emplode will not. I have some cover art (jpegs and gifs) as well as some random log and text files (lyrics) in my MP3 file tree. jemplode dumps them onto the player, emplode realizes they shouldn't be there and doesn't upload them.

When I try to download them later, they have their regular extension and then .mp3 added. i.e. filename.txt.mp3. If it's going to upload files other than mp3's, make sure it realizes that and then dumps them back off the empeg as such. It's a great way to back up or transport large files (digital pics backup, email, address book, etc.)