FileBrowse[ ] brings up a file browser to pick the name of a file.
FileBrowse returns as a string the absolute name of the file picked.
FileBrowse["name"] brings up a file browser with the specified default file name.
FileBrowse["name", "directory"] brings up a file browser starting in the specified directory.
FileBrowse can be used to find names of files for both reading and writing.
FileBrowse is intended primarily for use with local kernels.
See also: FileNames, Get, Put.
Note: this is an experimental feature, and in future versions of Mathematica it may not be supported, or may have a different specification.