Is there a completely free OS X hard drive cleaner?

I want to clean up the hard drive for my mac, does anyone know of a completely free program?
i mean, just erase free space, to clear those stupid files that take up needed space
For Is there a completely free OS X hard drive cleaner? try this:

• Yes there are. The one I use is OnyX . It erases a lot of unneeded files, logs, and cache on your hard drive. It also can check your hard drive status and repair permissions, as well as a few other things.
  
  "It allows you to verify the Startup Disk and the structure of its System files, to run misc tasks of system maintenance, to configure the hidden parameters of the Finder, Dock and of some of Apple's own applications, to delete caches, to remove a certain number of files and folders that may become cumbersome and more."
  
  You can download it for free here: http://www.macupdate.com/info.php/id/11582/onyx
  
  That version is for OS 10.5, but they also have the versions for OS X down to 10.2 on that same page.
  
• Here try this hope it works but I don't know if it is compatible with mac.
  
• do you mean format or erase it completely, if so then just use disk utility.
  
• Nope, sorry.
  
  There are some pretty cheap ones, however.
  
• dont you know you get what you pay for