Depends on your file system and more technical what not. But if you are looking for the quick kill (a la hidden files in Windows), rename the file with a "." at the beginning of the file name.
Eg: if the file was named file.png rename it to .file.png
EDIT: Pressing Ctrl + h will toggle hide status of hidden files in Nautilus (which is the default file browser in your distro, Mint)
Last edited by SkyEye; 02-07-2011 at 02:10 PM.