Ease of use when browsing a server in 1.2.3 Clients
(A few of these have keyboard equivalents you can see in the menus for the client...but those are different than these):

Option->Double-click to make the folder come up in the SAME window (this one really saves having a mess of windows all over when browsing a server!).

To go BACK in the same window, it's Option Command->UP Arrow.

To jump to the bottom of a long window (page to the bottom), use Command->Down Arrow.

Command->Up Arrow will open the Files folder.

Control->Up or Down Arrow will alternate between open windows in the client.

Highlight a user’s name in the user list and drag to the desktop to make a clipping of that person's name.

Control-F12 will bring up the “Secrets” box, where you can change custom icons and other secret commands (see other pages on this site for some of those).
NOTE 1: In Mac OS 9.x you need to use Control-Option F12 or you will bring up the F-keys dialog of the OS.
NOTE 2: On newer PowerBooks (year 2000 and above) use the fn key to access the F12 command.