When I run rake run:android, I get the error (I'm using Ubuntu):

Your java bin folder does not appear to be on your path.
This is required to use rhodes.

Here is the relevant part of my bash.bashrc file:

export PATH="$PATH:$HOME/ruby/gems/bin"
export GEM_HOME="$HOME/ruby/gems"
export GEM_PATH="$GEM_HOME:/usr/lib/ruby/gems/1.8"
export GEM_CACHE="$GEM_HOME/cache"
export RUBYOPT=rubygems

export ANDROID_HOME="/home/username/ruby_files/android-sdk-linux_86"
PATH="$PATH:$ANDROID_HOME/tools"

export JAVA_HOME=/usr/lib/jvm/java-6-sun-1.6.0_21
export JAVA_HOME
PATH=$PATH:$JAVA_HOME/bin
export PATH