Today I successfully installed BeOS on a new Vaio FX701 notebook.
The sound card and network are supported natively, although you cannot enable „real time audio“ in the audio mixer.
When you boot for the first time, you need to enable the safe mode setting "don't call the bios", and once booted, alter the file:
/boot/home/settings/kernel/drivers/kernel
In this file you need to uncomment the "bios_calls disabled" and "hlt disabled" instruction lines.
After installing the Radeon Mobility driver from BeBits, it works okay. If you don’t disable the HLT instruction in the kernel settings, OpenTracker will lock-up.
The screen, video card, sound card, network, and USB all work now.

Francois Jouen (fjouen@ephe-sorbonne.org) adds:
Installing BeOS on a Sony Vaio FX705
First of all, download BeOS 5 „Developer Edition“ from http://www.beosonline.com/ and burn it to a CD. This version runs perfectly on the Vaio FX series, since it includes both the Athlon XP patch and ATI Mobility Driver. The sound and network cards are also supported natively, although you have to disable „real time audio“ in the media preferences.
Installation:
When you boot for the first time from the CD, enable the safe mode setting „don’t call the bios“. Select the packages you want and start the install procedure.
Configuration
After the install reboot your computer and again use the safe mode setting „don’t call the bios“. Then edit the /boot/home/settings/kernel/drivers/kernel file and uncomment the “ bios_calls disabled “ , the “ hlt disabled “ instruction and all “ apm ” lines. See the example below:

# Sample kernel settings file
#
# This file should be moved to the directory
# /boot/home/config/settings/kernel/drivers/
#
# This file contains runtime configuration options for the kernel.
# If you're having trouble booting and can only boot when BIOS calls
# or multiprocessor support is disabled, uncomment the appropriate
# line by removing the initial # sign.
#
# multiprocessor_support disabled
bios_calls disabled
hlt disabled                      # don't call the HLT instruction in
                                    # the idle loop
# disk_cache_size 2048              # max number of blocks to cache
# SMP configuration and performance options:
# smp_io_interrupts enabled                     # handle I/O interrupts on all CPUs
# check_focus_cpu enabled                 # for description see Intel's IA32 manual, Vol.3
# max_cpu_number 1                                   # enable and use only the specified
number of CPUs
# WARNING: The following two options work properly only on certain chipsets
# and BIOSes. TURNING ON EITHER OF THESE OPTIONS MAY RENDER YOUR SYSTEM
# UNBOOTABLE.
# apm true                          # enable BIOS power management
# enable_shutdown true              # enable power-off on system shutdown
# debugging options:
# serial_debug_port 0x3f8           # use com1 for debug output (default)
# serial_debug_port 0x2f8           # use com2 for debug output
# serial_debug_output true          # dump kernel debug output to serial port
# syslog_debug_output true          # dump kernel debug output to syslog
# bluescreen false                                   # disable on-console kernel crash
display
# monitor_interrupt_handlers true   # monitor time spent in interrupt handlers
# kmalloc_tracking enabled                   # enable tracking of kernel malloc()
# load_symbols enabled                            # load kernel and kernel addon symbols
#bios_calls enabled   # added by APM driver installer
#apm false             # added by APM driver installer
#_apm true             # added by APM driver installer
#enable_shutdown true  # added by APM driver installer

Save the file and reboot your laptop.
Now you system is ready with the default graphics mode 1024×768, 32 bits per pixel, and 60Hz refresh rate.
You can use the Radeon Screen preferences program to set your resolution up to 1400×1050 pixels, but do not modify the default screen frequency (60Hz).
Enjoy the BeOS 5 Developer Edition, which is very impressive on the Vaio Laptop.