After being ripped off by hotels and airports for my Internet connections (with some places charging as much as 20 euros per hour, and your standard 10 euro per hour at CDG), I have purchased a 3G card from Cingular and a plan to use it internationally.
I followed the instructions on this blog post that covers another card on OpenSUSE 10.2.
With SLED 10 and the Aircard 875, the only difference is that I had to use a different vendor and product ID:
# /sbin/modprobe usbserial vendor=0x1199 product=0x6820
Or alternatively dump that in the /etc/udev/rules.d/51-3g-datacards.rules file.
Once you configure the modem in yast as described in the above blog post, go to NetworkManager, and select the "modem0" serial connection. There seems to be a bug in NetworkManager, when the modem0 connection is active, the icon seems to go away (am guessing its not finding the icon for it, and hence the applet vanishes).
A few minutes later, you will be online.
Am still missing some tools to determine the upload/download speed, anyone have some good pointers?