Well, unless you're an epic level hacker and compile the requisite modules... But then you might as well be running a modified power kernel, and you don't really need this question answered for you if you're that good.
Anyway, yeah, with the in-repo aircrack-ng, I had to bring wlan0 down, set it into monitor mode, bring it back up. I just ran airmon-ng on wlan0 with iw installed (just use "apt-get install iw" - it's definitely in devel, not sure if it's in the lower ones), and it did everything for me, and not only that, but it also spawned the mon0 interface - no need to take wlan0 down, monitor mode it, then bring it up again.
It's pretty cool. wlan0 is still in managed mode, so I think you can both connect normally and inject. IDK, I'm a newb to this too. I suspect you can also drop wlan0 into monitor mode, and thus do fancy things. *Shrug*
Yes, airmon-ng is pretty handy. It does have bugs though - it attempts to set the channel of the mon0 interface (if you pass one in, and bizarrely uses the legacy iwconfig to do so, despite knowing iw is present on the system) prior to issuing an ifconfig mon0 up, which of course fails; it doesn't retain the MAC address of wlan0 if you've faked it beforehand; and finally it doesn't issue a final ifconfig mon0 down, so you have to do so manually before faking the MAC yourself.
