Configuring ALSA to work with Gnome and K is still kind of tricky, but seems to be improving. I used alsa-source 1.03c, which is newer than what's included with kernel 2.6.3 or 4. Seems to be working fine now using the Intel8x0 module. Newer versions of ALSA also include suport for the built-in modem.

ACPI: Fine, but does not turn off backlight, Toshiba extras not supported on this model, system standby does not seem to work (system does not wake up).

Battery monitoring: Fine with ACPI compatible monitors, if ACPID is running.

Suspend-to-disk: Works, but I do not have the "hibernate.sh" script configured properly yet. Have a good-sized swap partition available (2x RAM)

PCMCIA: Works with yenta_socket configured as module. Don't forget to also install pccardd, part of the pcmcia-cs package IIRC.

Built-in ethernet: Works with rtl8139too module

USB: Works fine

DVD playback: Works fine, though Debian Sarge (as of April 04) seems to have introduced new bugs which cause video area to overlay all other windows. (xv bug?)

Hard drive, DVD: Support 32-bit transfers with DMA fine, providing that the kernel was compiled with the appropriate chipset support.

Internal modem: Untested, but seems to be suported by Intel8x0m module, included with ALSA 1.03c.

Have also tried with kernel 2.4.25 which mostly works too, but did not try to configure ALSA. As I had problems with the Intel8x0 module included with kernel 2.6.0-test4, so I'd expect earlier kernels to be problematic here too. Spare yourself the hassle and just use ALSA 1.03c or later.