I have a brand new Elcot Laptop (Acer TravelMate 5720), which came with Suse Enterprise and Ubuntu Hardy preinstalled. I prefer Ubuntu, but I found that it does not detect my wireless card. My wireless device is Intel PRO/Wireless 3945ABG.
If you have the same setup you can simply follow the steps that I did. To check what wireless device you have, run:
sudo lshw -C network
To get your card running, create a file in /etc/modprobe.d called iwl3945. Paste the following into it:
alias wlan0 iwl3945
options iwl3945 disable_hw_scan=1 hwcrypto=1
Now, you need to install the package linux-backports-modules-hardy-generic. To do this, you need to enable the Hardy Backports repository in Synaptic and then install it. If you are not sure how to do this, you can find instructions with screenshots here.
Reboot and your device should be working along with the wifi LED. You should be able to connect to unencrypted networks using this setup. A different network manager is needed connect to encrypted networks called wicd. To install wicd, follows these instructions. You should be all set now!
NOTE: All this information is also available in many scattered discussions in the Ubuntu Forums.