Hell, this may be illegal, but if the LA River plan is going to crawl upstream at a snail's pace, screw it -- the time to play is now! Not when we're 75 years of age. We caught this father/son urban adventure duo in Sherman Oaks paddling downstream towards Studio City. "Is this a tradition?" we screamed down. "Nope, it's our first time," the dad yelled back. We asked how he came up with......