To sign an APK with a debug certificate, use testsign.jar. The usage is very simple and doesn't require you to even create a test key.
Usage: testsign input.jar [output.jar]
You would use something like this:
java -jar testsign.jar Amazon_2.2.2_debug.apk Amazon_2.2.2_debug-signed.apk
adb install Amazon_2.2.2_debug-signed.apk