I guess it all depends on what type of folks you work for. I've left two jobs in the past for better pay and less work. I gave a verbal two week notice to the men I worked for. They were the top of the chain anyhow. Both of them understood why I was changing and they tried to get close to matching my new offer. Both said they would sure hire me back if the new job didn't work. I prefer verbal contact about things so serious. I also gave the notice asap before the word traveled the grapevine.