Since R3.1 will automount your Windows partitions, and because BeOS uses Windows-format TrueType fonts, you can have all of your Windows fonts available to BeOS without copying all of them over and duplicating hard disk space.
Just make a symbolic link from c:windowsfonts to /boot/beos/etc/fonts/ttfonts, rescan the cache, and you’ll have hundreds of fonts at your disposal.
Note: Don’t try this if you’re using ATM 4.0 in Windows. See this tip for details.