R.J.
As an adhd'er me'self...
It has to become "part" of him/automatic or he just plain and simple won't use it.
From your description he (imho) EITHER needs a laptop (and I'd suggest a used/refurb macbook which you can get for $500-$800 depending on whether you JUST get a refurb one, or get a used and/or refurb one) which he can just keep in his backback and carry around 24/7 ...
I'd suggest an actual laptop (and specifically a macbook for durability and portability and 'coolness' factor... which being the mum of an adhd kid you know that ANYTHING which prompts them to use it/carry it is HUGE, it's not a status thing... it's an end run against forgetting) instead of a netbook because MOSTLY, THOUGH, BECAUSE if he has to switch back and forth between a netbook and an actual computer for HW/Papers/fast internet/ etc... the netbook is going to get lost. It will kick around in the bottom of his backpack and get left in his locker, and get left on his desk. The MOMENT we ADHD types have to "switch" back and forth between 2 objects... 1 of them gets lost in the shuffle. WE NEED ONE thing that does everything, not 2 that put together do the same thing. Does it 'need' to be a macbook? No. But between a laptop and a netbook... a laptop... hands down.
OR
An iPhone. An iPhone ($50 for a 3gs) fits in a pocket and become 'bonded' to you / you never go anywhere without it. It doesn't have ALL the features you're looking for (no real keyboard, for example)... but it has
- a camera to take pics of important documents (I take pictures of assignments, recipes, worksheets, wine labels, shoes to buy for my son, a gazillion different visual reminders)
- a calendar
- MAPS!!! I can't tell you how useful maps and directions (for car, public transport, or foot)
- texting (both to send him reminders/ he can send himself reminders). EX my BFF will shoot me a text asking if I've gone to UPS or FedEx with the package I've promised (and promptly forgotten) to mail her that week, my mum will text to see if I can pick up her mail over the weekend (she texts requests contingent on my time, because she'll know I'll agree verbally FULLY intending to, without remember I'm gone that weekend... but texting means I have time to look at my calendar before replying), I'll send myself a text with my frequent flyer number and my confirmation number for airline tickets, etc.
- Voice notes (this isn't my schtick. But my son sends himself voice notes ALL the time -he's more audio, while I'm more visual)
- Aps (like "Find my iPhone" - umm... yes, before it becomes bonded to you, and the occasional 'oops' you just look up it's location on your computer and go fetch it, school aps, netflix/hulu, bus or subway routes, museum, Alarm Clock with MULTIPLE alarms)
- GPS tracker (so you can actually track his movements from home with it)
- iPod
- And, oh yeah, it also works as a phone.
An iPhone doesn't "compete" with a computer, even though it's like walking around with a spare brain in your pocket. You link it to your computer to update calendars etc (when you add to one at home or one on the go, as soon as you sync them, both calendars get the added info). But iPhones and computers are complementary. You can always set limits (which will be tested, and then he'll lose it for awhile, and earn it back and learn to stay in the rules), and disallow certain applications