I bought one, then went to Radio Shack and spent just as much ($2 ) on a PS2 keyboard connector to replace the Y end of the cable. I clipped off the Y end, shortening the whole cable to 2 feet, then soldered the PS2 connector onto the 6 wires. A straight-through connection didn't work, so I got out the old ohm meter and figured it out. The connector should be wired "mirror-image" for the signals, but straight-through for power.
The following is the wiring scheme, numbering the pins from 1-6 clockwise, starting from the square plastic key, and looking from the end that gets plugged in:
1-brn, 2-red, 3-blk, 4-wht, 5-yel, 6-grn.
Note that you'll probably need some electrical tape to keep your handiwork from shorting out on the metal shield, and if you shy away from fine solder work, maybe you should shy away from this - as the back side of the Radio Shack PS2 connector is not well suited for soldering. I expected hollow tubes, but it has pins similar to those that plug in on the front side.
I also shortened the mouse cable to 1 foot. It was much easier to do the soldering there, but putting the thing back together was a bit mechanically tricky.
All in all it all took an entire evening, but it is a great improvement over the stock i-o keyboard. My wife especially hated the disk-mouse, so life is good!
As stated before, the program disks enable the e-mail and www buttons. The sleep button worked straight away in W98, as did the roller-mouse. By the way, the mouse has logitech guts FWIW.
Thanks for the tip, jbarr!