If you have Ubuntu 10.04 and Aircrack you probably have installed the default version 1.0 but version 1.1 is out (april 2010) with many changes, the one I was more interested on was "Added the keys for interaction in airodump-ng" which lets you mark APs with colors, sort them in many ways, pause the display, etc... So I'm telling you how I installed it on my machine.
First I uninstalled ver 1.0 from Synaptic. On a terminal it would look like this "sudo aptitude remove aircrack-ng",
Then check your computer has the required packages (source: Aircrack's Readme File):
"* OpenSSL development package
* If you want to use airolib-ng and '-r' option in aircrack-ng,
SQLite development package >= 3.3.17 (3.6.X version or better is recommended):
* On windows, cygwin has to be used and it also requires w32api and gcc-4 package.
* If you want to use Airpcap, the 'developer' directory from the CD is required."
If you dont have a package just Google for the command you need to install it (note you don't need the windows packages :)).
Then you need to enter these commands:
I saw a bunch of errors during the installation but it still worked so DO AT YOUR OWN RISK.
tar -zxvf aircrack-ng-1.1.tar.gz
If when you try to run airmon-ng you get an error asking you to install iw do this from terminal:
"sudo apt-get install iw"
And that's it.
Here is a copy from aircrack's site of the keystrokes Airmon-ng can now detect.
[a]: Select active areas by cycling through these display options: AP+STA; AP+STA+ACK; AP only; STA only
[d]: Reset sorting to defaults (Power)
[i]: Invert sorting algorithm
[m]: Mark the selected AP or cycle through different colors if the selected AP is already marked
[r]: (De-)Activate realtime sorting - applies sorting algorithm everytime the display will be redrawn
[s]: Change column to sort by, which currently includes: First seen; BSSID; PWR level; Beacons; Data packets; Packet rate; Channel; Max. data rate; Encryption; Strongest Ciphersuite; Strongest Authentication; ESSID
[SPACE]: Pause display redrawing/ Resume redrawing
[TAB]: Enable/Disable scrolling through AP list
[UP]: Select the AP prior to the currently marked AP in the displayed list if available
[DOWN]: Select the AP after the currently marked AP if available
"If an AP is selected or marked, all the connected stations will also be selected or marked with the same color as the corresponding Access Point."
UPDATE: Ubuntu 11.04 has included Aircrack-ng 1.1 on their repositories, all you have to do now is "sudo apt-get install aircrack-ng" or install it from Synaptic.
No more error messages ;)