Using New> Android Project> Create project from existing source is the
right way to do it.
Make sure to select which Android target you want (1.1 or 1.5): the
new project wizard will automatically select the right sample
directory for you. Then select "Browse" and the Snake directory. It
should then fill the properties at the bottom of the new android
However you should not put your workspace in %ANDROID_HOME%\samples.
Leave it somewhere else (My Documents, whatever). I suspect you get a
conflict because Eclipse tries to create a project and there's already
a directory of the same name.
In either case, can you look at your_workspace_dir/.metadata/.log for
a more verbose error and post it?