Search for "Huawei EC321" in google images to find a lot of photos about it.

This is the "default" CDMA modem card from China Unicom, the biggest ICP of CDMA connection, thus it is widely used in China.

Use it as any other modem, it do not require any other special configuration. However I don't know how to use this device to send/receive SMS and make mobile telephone calls (it is supposed to be able to do both). Since SMS & mobile phone call are not core function of CDMA modem, I'd just suppose it's usable.

Here is a Chinese explanation and guide on how to use it, with screenshot.
http://nemo2050.spaces.live.com/Blog/cns!E8CBAD79AB611748!393.entry

This device does not work on Ubuntu 7.10 (kernel 2.6.22). Refer to this
http://www.nabble.com/Huawei-EC321-CDMA-PCCARD-support-broken-tt14680470.html

I am the anonymous user who sent the message "doesn't work in Ubuntu 7.10". That message is not true.

The truth is it takes a while until it's usable. I simply didn't wait long enough. The card is usable after plugged-in about 1 minute.

Now I am using this very card on Ubuntu 7.10 and it works fine.