Most people have 2-3 times as many ideas than they can do in a day but adults with ADHD often have 5-10 times as many. What’s worse is that ADHD adults usually have problems with working memory, distraction, impulsivity and disorganization so it’s easier for us to have those ideas to slip away. If an ADDers writes their ideas down on random scraps of paper, they might as well toss em out the window. Better chance of finding them.
Glen at LifeDev has a good post on 25 tools to capture those fleeting ideas, divided into analog tools, web, mac, windows and phone based tools. I like the Recording MP3 watch, and have recently been using one of the small moleskin notebooks which I wish I got years ago.
Different tools work for different people and most need more than one tool.
One thing to keep in mind that capture is just the first stage and then the filtering/filing/prioritizing needs to take place. Just because you think it’s a “good/useful/interesting” idea doesn’t mean you have the time, money, energy and resources to do it, and you usually should be willing to decide what you’re going to say “no” to in order to say “yes” to the new idea, but that’s another post.
I would also recommend Microsoft One Note. It is invaluable as a way to organize all my ideas. It can be shared across networks so you can work with it online and such and the organization options are kind of endless. Also, it integrates fluidly with the other parts of Office, so its really easy to transfer the idea to a document. That and you can run it in your SysTray and just jot notes.