Rapidspread does that for you. It is a free web service which will upload your files to multiple file sharing sites like Rapidshare, Mediafire, Zshare and many others all at once. Theoretically Rapidspread allows unlimited file size, if the individual file sharing sites is not having such restrictions.
Once you have selected the file from your PC, RapidSpread will ask you to select the servers where you want to upload the file.
Once the upload is complete, RapidSpread displays a URL to send to your friends as well as direct links to your file on the supported hosts it’s been transferred to. Anyone that uploads files on a regular basis will appreciate the simplicity and power of RapidSpread. Try it out today!