There are too many softwares available but most simple with tiny size software is HJSplitter. It has a simple user interface. With increasing media size one may always get a situation when larger files cannot be send via email or cannot be shared on sharing websites like Mediafire (limit 200mb), Rapidshare, file sonic etc. here is when HJSplitter comes into the picture, it split files into bite to MB sized pieces which can be rejoined to form an original file. The original file can be split according to desired sizes so that sharing according to size is not at all a problem on sharing websites or for sending files via emails.