Well, 99% of the time I haven't had any problems with taking a board on the plane but that other 1% is a complete downer - especially if you're in a rush. It's just like when you go through immigration - it only takes that one guy with the stamp to give you a red mark and it's ultimately at their discretion.
The thing to worry about these days more than having to check it is whether they're going to try and charge you the "sports equipment" fee. I'm definitely not trying to pay $100 to check my skateboard. Now, if you take your trucks off and carry your board they can't really say that's sports equipment and surprisingly enough most people who don't skate and work in TSA won't even make the connection that it's a skateboard deck - I've told them it's an art piece. Don't carry your board intact in your hand though, I mean you can, but I feel like when it's strapped to your back people don't pay as much attention and it also makes it seem more like 1 piece of luggage rather than 1 + a carry on. No one's so much bothered me in the States about it and I think the only time I was forced to check it was in London? Or maybe that was in Qatar just on a British Airways flight - either way it was a bitchy old British lady. In countries where less people skate is where I think you run into more problems because even skate tools are pretty foreign to them. They took away my t-tool in Lithuania that didn't even have the little screwdriver bit in it but they still let me take my board on the plane. I was like, yeah, I'm going to find the three bits on the plane that fit this and take apart the plane in flight, nut by nut.
If you've got the room to stuff it in a bag though, that's full proof.