Krusader is an advanced twin panel (commander style) file manager for KDE and other desktops in the *nix world, similar to Midnight Commanger or Total Commander. It provides all the file management features you could possibly want along with extensive archive handling, mounted filesystem support with a built-in mount manager, search module. It also has an internal viewer/editor. You can also rename whole batches of files.
It also has FTP/SAMBA accessing with SFTP/SCP support. So you can safely send your files accross the network. It is a nice tool and I must thank Iain for pointing out this one.