I found a neat set of command line utilties called osxutils, available on the sourceforge osxutils project page. The package Installs with an easy Apple installer. Summarized from the Read Me file, the included utilities are:

• lsmac: Lists directory contents akin to the traditional ls command, but also shows Finder flags, heritage File and Creator types, displays size in human-readable format (i.e. 1.2 MB), and shows source files of Mac OS aliases.
  
• setfctypes: Simple, direct interface for setting File and Creator types; processes many files quickly.
  
• setfflags: View and set file Finder flags
  
• setfcomment: Sets file comments, both Mac OS 9 viewable Desktop DB comments and OS X Finder comments.
  
• cpath: Copies the current working directory path ($PWD) directly to the clipboard
  
• setsuffix: Set, replace and remove file suffices/extensions
  
• mkalias: Create MacOS aliases with an interface similar to that of ln.

I'm finding lsmac particularly useful and have aliased it to ls in my ~/.tcshrc file.

[robg adds: Normally we don't run general announcements of software packages, but in this case, the osxutils package is an extension of the lsmac script posted here a while back, which seemed relatively popular based on the comments -- so I thought this may be of general interest.]