It is actually a little harder than this, since JAVA is statically compiled. You can't have a class referenced in code if it's not available in the JVM, even if that code branch is never executed. So this will not work: if (ANDROID_2_1) { BluetoothManager.doSomething(); } There are a few good tutorials for handling this, while avoiding reflection. They take advantage of JAVA's lazy loading of static classes. The official Android blog has a post here: http://android-developers.blogspot.com/2009/04/backward-compatibility-for-android.html and here is a great, detailed tutorial: http://devtcg.blogspot.com/2009/12/gracefully-supporting-multiple-android.html With that said, sdk 2.1 isn't terribly different than sdk 1.6, really. You can write most apps using 1.6, and should for now. Code modifications go through a lengthy deprecation period before being considered for removal. Should Google really feature-freeze a platform because a single phone got released?

Fine, but you can't do the research if you don't have the genome. The title of the article wasn't "Cancer Genome Sequence, Cure Eminent."