Hello!
I've installed Ubuntu 10.04 and Virtualbox 3.2.4 (not the ose version).
and I've "windows xp sp3" as a virtual machine but i cannot access to the www.
If i go to the control panel, there isn't any network card.

I try to use both the Bridge and NAT mode, but the problem goes on.
In the advanced configuration parameters you have to choose a network card in a list:
-PCnet-PCI II
-PCnet-FAST III
-Intel PRO/1000 MT Desktop
-Intel PRO/1000 T Server
-Intel PRO/1000 MT Server
-virtio-net
but i don't understand which is the right one.

Thank you for your attention.

the easiest way to access internet from virtual box was in my case, to connect (real) usb wifi dongle to virtual machine

Intel PRO/1000 MT Desktop

This is the one my VB defaults to under both Linux and Windows and seems to work well for my guests.