Wow, once I learned a few Mac OS X keyboard shortcuts, I like the Finder much more. It was freaking me out that the [Enter] key doesn't actually open a file or directory, it just lets you change the name. The keystrokes are much different than Windows, and it takes a while to get used to them. But once you start using them they're easy to remember.

So, here's a list of the Mac OS X Finder keystrokes I use a lot. The "command" key is also known as the "Apple" key.

                 Keystroke                   What it does
                        [Enter]                             Lets you change the name of the selected file or folder.
                   [Command][O]                     If a file is currently selected, it will be opened with the default
                                                               application.
                                                               If a directory/folder is selected, it "opens" that directory
                                                               (moving you into the directory).
                    [Command][i]                     Shows the Get Info window for the file or directory.
                    [Command][UpArrow]           Moves up one level in the directory hierarchy.
                                                               The arrow keys The arrow keys let you move up/down/
                                                               left/right in the current
                                                               list of files.
                    [Command][delete]             Delete the selected file(s) or folder(s).
                    [Command][1],                    Toggles the Finder view between Icons, List, and Columns.
                    [Command][2]
                    , or [Command][3]
                    [Command][Shift][g]           Show the "Go to" window.
                    [Command][n]                     Open a new Finder window.
                    [Command][w]                     Close the current Finder window.
                    [Command][f]                     Open the "Find" dialog.
                    [Command][spacebar]          Brings up Spotlight.

FWIW, the "Go to" window is the only way I know to get to the /tmp directory.

There are more keyboard commands available than what I've shown here, but these are the ones I use. (For the other tasks I don't mind grabbing the mouse.)