Comprehensive Halo Theme package
St. Joan put together 5 separate Halo themes, complete with wallpaper, icons, cursors, and sounds. The whole kaboodle is 9 megs.
FunkDaddy's Halo Icons
Collections of 27 icons (the link points to a preview) for both
Windows XP (48x48, 269K) and
MacOSX (128x128, 847K).
Halo Font
A usable version of the until-now nonexistent "Halo font" - the font used in the Halo logo. Though there's still no official version,
Will Turnbow took the time to create a mock-up of his own. Available in TrueType format, for Mac or PC. Also available as a Type 1 Postscript font.
Halo WinAmp Skins
A selection of ten different Halo-oriented skins for audio player WinAmp. Created by Christian Bender.
Halo Windows Theme
An installable Halo Theme for users of Windows 98, Windows 95, or Windows ME. Facilitated by
Doomsdeath.
Warbow's Halo Cursors
Windows (any flavor) cursors - spinning warthogs, etc. Can be previewed
here.
hope they help