Modafinil, dexedrine, methylphenidate etc. aren't so much intelligence enhancing as they are performance enhancing. I have taken dexedrine a handful of times when I have needed to get a lot of boring work done. It's like motivation in pill form. It won't make you any smarter, but it will boost your energy and make anything seem more interesting. When the high wears off, you're left feeling slow and dumb for the rest of the day, especially if you are sleep deprived as well.
These drugs are better than caffeine for getting work done, but anyone who does not have a prescription should be wary of taking them too often without substantial breaks. Then again, I don't know a single person with a prescription for one of these drugs who truly needs them to achieve a level of 'normal' function. It is almost too easy for a normal healthy person to go to a psychiatrist and convince them to prescribe an ADHD drug.
Ethically, this is a difficult subject. For example, a hard working B-student could have been an A-student with just a month's supply of ADHD drugs. On the other hand, tons of kids who don't really need the stuff get it anyway. You just have to be informed. Then again, you should not have to be forced to take drugs just to keep up with other students. Some schools are looking into including the use of these drugs under their academic integrity codes, or even instituting drug tests to screen students. Given the ease of attaining a prescription, this will be ineffective at curbing anything. Educating students effectively on this subject is a better route.
There are also the racetam drugs, of which piracetam is the most popular. It's available without a prescription in the U.S. I bought a 700g tub of this stuff last year. Most users dose between 2 and 10g spread throughout the day. This is almost a wonder drug in that it does a lot of awesome stuff without the side effects of other performance enhancing drugs (except that it makes you poop a lot at first). Effects include increased concentration, getting out of bed is dramatically easier, vivid dreams, better motivation, potentiation of some other drugs (especially alcohol) and more.
My personal experience with piracetam only gave me marginally increased concentration for the first week, and slightly higher motivation to do whatever menial tasks I had to do (cleaning, laundry). But, I have never had an easier time getting up in the morning. When I opened my eyes I was instantly alert and ready to go do stuff. When I took 1-2g before bed, my dreams were sometimes terrifying in how vivid they were. The same dose before a night out made 1 or 2 drinks seem like 5 or 6 (a dream for someone on a budget). Sadly, the effects on concentration and waking up only lasted about two weeks. Some users also complain of headaches. If you are considering purchasing and using piracetam, make sure you also buy an equivalent amount of choline (any kind). Take the two together (you can take more choline if you really want to, but I found it sufficient to take equal amounts in weight), to prevent headaches.
