How do I delete info to free up memory space?

My visor (it's kind of old - maybe 5+ years now) has refused to add any more information until I free up more memory space. I added the email function which I now realize doesn't need to be there. But I can't seem to delete all the 500+ messages easily. Will this even help the situation? I am leaving my company at the end of this week and don't want to lose any of my new contacts, etc.. Where do I find the Application Launcher to understand where all the memory is sucked up in?