I would like to completely disable UDP packets from exiting or entering my computer(Ubuntu 11.04), how would I go about doing this? What are the downsides to disabling UDP packets? The reason for doing this is to prevent my real IP from being broadcasted.
and killing the processes that have open UDP sockets (all the processes listed),IF YOU'RE SURE YOU DON'T NEED THEM! I'm almost sure that you need them.
This being said, I must confess that, in my 45 year career as a sysadmin on Unix and Linux with the last 20 years in security, I've NEVER encountered a situation where turning off UDP was a good idea. It seems like you're trying to secure your system by randomly turning things off, without understanding what you're doing, or how security works. Please don't.