OK!
I have a site which caters for all the cellphone and mobile users. It have ringtones, software, games and other stuff for downloads. It also allows user to upload their own files.
Now wat i want to do is that sometimes users upload zip files which contain ringtones. Later when they wish to download it to their cell phone, they cant download zip so is there any way that if user downloads a file it unzips on the server and then get downloaded.

And secondly any way to convert a file on the server, like a midi file to be converted to mp3 and get downloaded onto a cellphone.