There is a distinct problem with recommending 'back to school' technology and gadgets, especially to the Generation Y. By definition, young consumers are not always swayed by the most popular, and often retain a high level of free choice - even if it's different, quirky or unconventional.
So instead of pontificating to the masses and stating what you should and shouldn't buy for the upcoming academic year, I'll give you a few ideas of where to focus and allow you to find the best deals (before the rush kicks in and the prices go up) and you can find the best based on consumer and site reviews, popularity, reliability, support, compatibility and of course - price.
Handy tip: Try and use Amazon in your locale as a good benchmark when buying tech products. You don't need to buy from Amazon but the product reviews, data and information is most handy. Don't necessarily focus on the good reviews; check out the bad ones too, because these can raise unspoken compatibility issues you wouldn't find elsewhere and gives you a sense of balance and perspective from your peers.
Moving into halls of residence on campus?
You're probably a first year if you're living on campus. Not all tech works in campus accommodation, and be mindful of the fact you'll probably only have a couple electrical plug socket!
Netbook: they're cheap, they are tough, they will last you all day on campus and perhaps more, and are good enough for the vast majority of things that you need it for. Plus, if you are one for open-source operating systems, netbooks are often sold without a Windows license so it cuts down the price dramatically.
Games console: when you start university in a completely new setting, brand new people and no idea where to start, remember the iGeneration gaming culture. Consider which console is the most popular amongst your corridor, block or friendship group and go with that choice. Gaming is a big aspect of modern day socialising, and it's important to wind down and have down-time too. This gives you the best of both worlds.
Digital voice recorder: many lectures are recorded nowadays but some lecturers avoid it because of copyright and intellectual property - or rather, that's the excuse they give. Not only is it useful to go over your recorded lecture notes at the end, it puts you back exactly where you were to refer to it later. Just don't get a digital voice transcriber; write your notes up and commit it to memory, because come exam term you will need it.
Pocket projector:no student will actually need one, but the cool factor is beyond the scale. Just think of what pranks you can pull - perhaps during nighttime hours and with the side wall of the library...
Don't get a wireless router or any device which relies on a wireless connection. The chances are in halls, you won't get wireless signal and will have to rely on a single Ethernet port in your room. Sure, you could buy a wireless device but these are often restricted (and usually very securely) and don't work from your study bedroom to prevent bandwidth abuse.
External hard drive: while your university will have student storage space, those living off campus will struggle to use it unless they manually bring their laptop or netbook to campus. If you have a desktop PC, you're stuffed - unless you fancy using VPN which many universities don't support. An external hard drive will be more than enough to backup your entire machine many times over, or consider a free alternative by backing up to the cloud. They're not brilliant though, and I would still definitely recommend a external backup drive instead.
All-in-one printer: though many don't scan books anymore outside of the library, it's still more cost efficient to have an all-in-one scanner and printer. Check beforehand that it is compatible with your operating system (Windows 7 and Ubuntu 10.04 especially) and that the printer ink cartridges are from an easy-to-buy, popular and reputable brand like Epson, HP, Brother or Lexmark.
Media streamer: who says you need to invite your friends over to your tiny, cramped bedroom to watch a movie on an equally tiny laptop screen? Media streamers bounce your videos from your Windows PC to the widescreen TV downstairs. Unfortunately a streamer usually only supports one Windows PC at a time but they're easy to configure for other computers; though it can be annoying if you're doing it three or four times a day.
Don't get a 3G dongle or mobile broadband, as tempting as it might be with the potential for higher speeds than some home broadband deals in low-end student housing. Unless you haemorrhage cash or have a money tree growing in your back garden, avoid it like the plague. Your university will have super-fast Internet speeds so provided there are no restrictions on your bandwidth, stock up on TV and movie downloads while on campus.