Depends on the company in my book - if you can't wait to get out of there and don't mind burning a bridge or two behind you - by all means - you should just walk out when it's convenient for you.

Noticed a pattern of "pack up your stuff - today is your last day - sorry we didn't give you more notice"? They've shown their true colors already and you can do as you please.

My experience was different.

Was working with a fabulous company for almost 3 years and really needed to change my situation. Got an offer with a local company for 25% more than I was making and accepted on the spot - but told them I couldn't start for 2 weeks. "No problem" they said. Went to my (soon-to-be) ex-employer and let them know I would be leaving for another job. Sorry to see me go - but they wished me well. "When do you want your last day to be?" they asked. Having just (mostly) finished a contract, with not much going on - I told them "two weeks" and they agreed.

I will be forever grateful for that time. I had almost 2 dozen meetings with co-workers who had become friends and I was given a chance to say good-bye, explain my reasons for leaving (instead of leaving that to company gossip) and get a good sense of closure. I've stayed friends with almost everyone, including senior management - and learned that part of the reason is the 2 week notice I gave them.

Sometimes a little mutual respect and consideration are good things.