Ever get bored with your job?

Do you ever get bored with your job? Is it because of what you're doing, or because of your working emvironment? Do you prefer a more stable job, or something exciting, where you always confront new things? Do you change your job quickly if you get bored?
I'm asking because I had a talk one of these days with a very good friend of mine, who was saying that after a period (around a year usually) he gets bored of his job, and quits... Even if he has a good salary, even if he's working in mass-media (and you know things aren't that boring in this domain!), he still gets bored easily

Until now i didn't get bored :)
I like my job and i don't think i would get bored to soon.
I meet new people every day and i like that.
Even if i got bored someday, i think after all this time i have worked in this area i would wait for the feeling to pass :D It would be a pity to quit, afterall i got used to it and i may advance someday ..

There are times I feel like I hit a plateau. In such cases I might try a small vacation or just re-think my duties and how I can do my job. Maybe come up with something new that would help me see it as I did before. In a way it's a normal feeling to get bored, but it shouldn't be something long term.