Today I decided to start developing for the Android OS. I went on their website, downloaded all the required software (Eclipse, The Android SDK, ADT Plugin for Eclipse etc.). I followed the "Hello World" tutorial supplied (link text). I have it using the Android SDK 2.1. The program worked almost flawlessly. It runs fine on the Android emulator, but doesn't install on any Android phones. I don't own an Android phone, so I had three of my friends try to install the program on theirs. The phones we used were: ROOTED G1 running 2.1 Droid running 2.1 Another Droid running 2.1 I emailed the .apk to myself in gmail, and accessed it via the Android emulator. It ran and installed the package just fine. However, when my friends tried to install it on their phones, they were all met with this error: "[Parse Error] There is a problem parsing the package" I'm wondering if anyone has any suggestions as to what may be wrong. Thanks for your help.