I am using 5800 with my Nokia 232, and I am using AT&T Keep In Touch
Modem Model 3762. It works great & does not a need modem configuration. It has
an autodetect feature that lets you use cellular or landline without any
configuration change on your modem string. You can order the cell-cable direct
from AT&T for $69.99.

The AT&T modem came preconfigured with a Motorola driver. You may have to do a
firmware upgrade on the notebook in order to make it recognize your Nokia
232 (they give you the driver on a diskette). It is very easy.

There is also a new firmware upgrade. I just downloaded it yesterday from the
AT&T BBS, which is to be used for a modem that is connected to Zaurus or
Newton. It will enhance your fax transmission. The bad thing is it draws
toooooo much power from your Z2. You have to use an AC adapter.

I heard that Megahertz XJ3114 ($69.99) is the best modem to use with Z, but
when I call Megahertz, they don't have the cell-cable for Nokia 232 yet
(it was March).