Took Adderall for a year, but really didn't like being on speed. Even at first, where it seemed like I was focusing harder and working more, I'd miss obvious solutions to problems and instead spend 4 days in a meth-induced craze over-engineering the problem in my boxer shorts.
I quit about 8 months ago, and pretty much just smoke weed now, which I personally feel helps the ADD by attacking it in the opposite way -- instead of being super focused on whatever one task I started on at the beginning of my pill, I'm constantly forgetting what I was doing, and rethinking it. As a programmer, I've found that's actually an awesome trait to have. I'm way too high to concentrate on a bunch of shit at once, so I clear off my desk, close my AIM, and zone out to some Pink Floyd while thinking about the problem at hand. Usually, if I was planning on writing 500 lines of PHP today, by the end of the day (and a couple of bowls), I'll have solved the same problem with 30 lines of Python. Plus, I was high the whole time, which is awesome.
It took a lot of discipline to learn how to work when stoned, and sometimes I still wish I had motivation-in-a-pill (instead of smoking away all my motivation and having to find the will to work anyway), but I'm much happier with this than being on "amphetamine salts" and feeling my heart beating out of my chest and forgetting to eat. Shit, these days, I never miss a meal, my coworkers know I've always got the munchies
EDIT -- which brings me back to my original point, I'd really like to try Modafanil/Provigil or Adrefanil (metabolizes into Modafanil). These are drugs for narcoleptics that supposedly give you the always-alert feeling of Adderall without turning your thought processes into a Muslim extremist that's hijacking your thought processes and flying them into brick walls. According to the testimonials I've read, you stay awake all day, sleep 3-4 hours per night, feel calm, clear and refreshed and never "speedy" or "shakey" or "forget to eat today". Anyone in SoCal wanna try a box with me? I still can't find Modafanil, but Adrefanil starts at like $130 over at Biogenesis, and they ship to states.