OK, I am a total noob to roms but am really looking into rooting and installing roms on my phone. My question is can you install multiple roms on your phone at once or do you have to install one, then uninstall and install another? Also, I have done some research but still don't know the answer to this....what is the main difference between different roms like sholes, BB and smoke glass? Are there pros and cons to each??