I actually like to give a good amount of notice, as it allows for a good reference. There is one job however that I didn't give notice to when I left but I don't plan on using them as a reference because well mutually screwed each-other over.
I was working there hourly and "part time" for the better part of the school year while I was in grad school, it was supposed to be a 15 to 20 hour a week job, but my "part time" still had me working about 35 hours a week just to keep up with the workload. I told them several times throughout the year that they should really have someone do this position full time, but they didn't catch on and I slowly fell behind in the work because I could not go to school, do my 20 hours of work study for school and work 30+ hours a week for them.
For about two months before the school year ended I told them several times, once the school year is over I can work full time and we can get caught up, they said it was a good plan and that they could hire someone full time in the fall. I fully expected to have the job and make some good money over the summer. After leading me along for a while they brought someone in to "help" and had me do about a couple weeks of training for the new guy, so they phrased it to me that instead of having someone full time, they had two part time people, again I saw through their lies.
After the new guy knew enough about the job, they sat me down for the speech: the classic, this new guy is going to be working full time, he is now your boss, and will be reporting to the guy who was my boss... and by the way we are cutting your hours down to 10 from the original 20 as we probably won't need as much of your time now that we have someone full time.
I saw right through it and knew the only reason they kept me around for the 10 hours is that the knowledge transfer from me to the new guy was incomplete and some weird situation might arise where they needed my help.
Right around this time the semester ended and I got my grades, I had submitted forms to have my job count as an internship (which I had to pay the school processing fees for) and had an incomplete listed as my boss had not filled out the paperwork.
At our little chat I reminded him that he needed to fill out the paperwork, so I didn't loose money and could get credit. At the same time I told my boss it wasn't worth my time to commute out to the office and that I would be working from home, he looked at me and tried to figure out a reason for me to come to the office as he knew they might need my help on some random thing, and I could teach the new guy some tips or tricks.
Anyway I finished my projects the next day and stopped taking new projects and stopped responding to their e-mail. One day about 3 weeks later my boss called me at 10:00 am and asked if I still worked there, I was sleeping, but he obviously had a project with a big deadline. I told him that I didn't work there and wouldn't work there unless the internship paperwork he kept not filling was submitted.
About a week after I told him I didn't work there he called and asked me a question about some weird thing, and told me he finally submitted the paperwork. I again reminded him that I didn't work there any more and that if he needed my help I would be more than happy to come back on as a contractor for $100 an hour with a minimum commitment of 5 hours in any week they used my services, this was 5 times the hourly rate they were paying me earlier.
We both knew what he was looking for was a 15 minute answer, but they had been working on if for half a day before calling me. He quickly agreed to my demands without any hesitation, and asked me how to fix the problem. This lead me to believe he had no intention of paying once I gave him the answer, so I told him to call me back when he had two copies of a 1099 contract on his desk signed by the president of the company and himself, I would then gladly drive over and pick up the contracts at the same time that I showed him the answer to the problem, he never did call back.
About a month later I ran into my replacement at a bar, it took the two of them 2 days to figure the problem out, in the end they would have probably saved money paying me the $500, but o well such is business.