Android development

when you plug in a nexus and you do
./adb devices
you get:
List of devices attached
???????????? no permissions

What you need to do:
./adb kill-server
sudo ./adb start-server
* daemon not running. starting it now *
* daemon started successfully *
./adb devices
you get:
List of devices attached
HT019P803628 device

Then, if you don't have an emulator running, you can do:
./adb install ../platforms/android-2.1/samples/ApiDemos/bin/apis.apk

To get the debug trace on the host computer:
./adb logcat