(CNN) Marijuana smokers now have a new place to put on their bucket lists: Alaska, which on Tuesday became the third state to officially OK marijuana use.

Following Colorado's lead, voters passed the Alaska Marijuana Legalization ballot measure in November. Legalization became official on Tuesday, which means that now \"the use of marijuana (is) legal for persons 21 years of age or older.\"

There are limits to this law, as there are in similar ones in other states. People still can't legally have more than 1 ounce of marijuana on them. Nor can they harvest more than 4 ounces in their home. And consuming marijuana in public and driving while high are no-nos.

Then there's the fact that the law isn't fully implemented yet. The regulatory structure allowing for entrepreneurs to set up shops like those found in Colorado is still in the works, so right now no one can legally make a living selling the drug.

Not to mention that, under federal law, marijuana is classified as a Schedule 1 narcotic. That makes its use a federal crime.

Still, as in many states, there seems to be movement in Washington on that front. U.S. Attorney General Eric Holder told CNN in October he is \"cautiously optimistic\" on the subject of marijuana legalization. Holder said the Justice Department is focused on marijuana distribution to minors, interstate trafficking and drug violence, not incarcerating \"low level people who are simply there for possessory offenses.\"

In the absence -- some might say in defiance -- of any sweeping federal change on marijuana, some states have taken the initiative.

Twenty-three states still prohibit cannabis outright. But the rest of them have either legalized medical marijuana or decriminalized marijuana possession.

Colorado became the first to go one step further in legalizing pot, followed by Washington state. And now there's one more in Alaska.