There is one other thing to think about when it comes to this topic, what is legal and what is rational.
For instance, what do you think would happen if I carried any one of these down the street...
Now sure, those are all designed to look like REAL guns...but understand to the lay person if it's black and has a barrel it's a gun. Also, to many people the color part is only an option. If it has a barrel and looks similar to a gun, it's a gun (think of real pistols that are silver or "chrome" rather than black.) The first time I showed one of these guns to a friend of mine who is a police officer the very first words out of his mouth were "Oh yea, if I saw you walking down the street with this I'd shoot you."
Remyrw is right as far as researching what the law is in your area but you'll also want to use some common sense when it comes to carrying your marker in public. My guns all have cases and I treat them as though they were real firearms because, while this may be overkill, it means if someone assumes they are a real gun I'm not going to be in a position for them to think they need to be worried or call the police.
Side Note: I may be a bit more sensitive to this than most. In the mid to late 80s here in SoCal, some boys were playing laser tag one night at a school. At that time, they sold a laser tag set that came with a shiney black plastic gun with a red stripe down the side and a red light along the side that would light up when the gun was fired. The gun is the one at the top in the picture below. The white was not offered until after this incident. You can see where the red light on the front of the gun is in this picture especially on the white gun...it's where the bright red line ends towards the front and you see what looks like a darker red line.
Someone called the police and reported there were "figures in black running around a school with guns". The police came and, taking the call seriously, got out their shotguns. While they were on campus investigating the call, one of the boys came around a corner in front of one of the officers and, believing the officer was one of his friends, aimed his lazer tag gun at the officer. The officer, not knowing in that split second whether or not the gun the boy was holding was a real gun, fired his shotgun and killed the boy.
A few months after this some friends of mine and I were playing with the same guns at a school. Before hand we had called the local police and informed them of what we would be doing, where we would be doing it, and between what times we would be doing it. Unfortunately the dispatcher we informed did not pass this information on to the dispatcher who releived her early in the evening. When the call came in that there were "people in black running around a school with guns", she dispatched a unit to investigate. The unit pulled in the parking lot with lights off.
As I was chasing a couple friends of mine around a building towards the parking lot, my friend in front was lit up like a Christmas tree from the spotlights on the cruiser and shouts from the officers to, and I quote, "Drop it, Azzhole!" who were behind their front doors with their weapons drawn, ready to fire. My friend spiked the gun like a football, raised his hands, and shouted with deathly fear in his voice, "It'slasertag! It'slasertag! It'slasertag! It'slasertag!" Thank god the officers didn't shoot and everything was fine once we had straightened everything out.
This was before 9/11, before North Hollywood, before Oklahoma, before Columnbine, before Boston...before people would go on a shooting spree in a mall, movie theater, or school. Today, with these kinds of shootings becoming more commonplace, police are far less likely to verify you're carrying a toy gun rather than a real gun before they make the decision to fire.
Sorry for the long post, guess you struck a chord.