You have got lots of different file formats on your computer: jpg, jpeg, gif, bmp and png or rtf,txt,doc and pdf for instance. The big question that comes to my mind is why do we need that many formats. Most file formats offer no gain over the other, would not it make sense to convert all files of a certain type to one format only ?
Omniformat is able to convert 75 different document types, the emphasis lies on text and graphic documents. I can think of one reason for myself to convert documents to different formats: I sometimes download files that I´am not able to edit because they have been either created on a different operating system and my system does not support editing the file or I simply do not have an editor at hand for the document.
This could be the most prominent reason for most users of omniformat but there are or course more. Omniformat is able to watch a folder for new documents. Once a new document is added to the folder it will be automatically converted to a chosen format. An image could be converted to a text document using OCR for instance.

Convert a file before downloading
Convert Pdf To Text
Format Factory
Convert PDF To Word And Excel