Porter took his first step a few months ago but staunchly refused to ever take more than one or to stand without holding onto anything. At his 15 month check-up, his doctor said that if he wasn't walking in 6 weeks, she would re-evaluate and see if he needed physical therapy. Less than a week later, he was walking.
At first I tricked him into walking by having him hold a toy that I was also holding onto. I would then let go and he would take a step or two on his own without realizing it. That built his confidence and two days later, he was walking across the living room!
He still can't stand up without pulling up on something so he will pull up, walk until he falls, then crawl to the closest piece of furniture (or me) and pull up and then walk again.
I'm still surprised every time I see him sauntering across the room, but I'm so proud of how fast he caught on! He's finally a toddler!