I've been using computers since I was 5. First an Apple ][e compatible, then an IBM PS/2 (yes a genuine IBM!) we purchased at auction, a 386DX40, then a Pentium 90, Pentium 233, then various Celerons, Pentium 2/3/4 and so on.
The most notable advances in my experience were the jump in CPU speeds between the 386s, 486s and then the early Pentiums, the availability & ever increasing size of HDDs, the advent of the modern sound card (before that all we had were beeps!), and graphics cards which significantly boosted performance of 3D gaming.
However for the last 10 or so years I've not really been wowed much by new hardware. This period of time also corresponds to my working life span and I mention this as suddenly I could afford stuff yet I didn't buy much nearly as many gadgets as I could have. CPUs and GPUs got faster, and added more cores, but fundamentally the improvement was not so incredible, at least in my mind.
On the mobile front I continue to use a 5 year old phone as I find modern phones both overly expensive and buggy. I miss the days when you'd buy a gadget and it would actually work as specified, without any firmware or other software upgrades.
That said, in the last 12 months two tech things have really impressed me.
The Solid State Disk is the first. I've had a pretty bad experience with my OCZ Vertex, yet I'm madly in love with its speed. I've sent it back for replacement twice, and spent at least 3 full days messing with various firmware & backup recovery. But when the thing works, its amazingly fast. Windows boots in less than a quarter of the time it took on a HDD (identical image, I mirrored the disks) and I no longer think about whether I'm already doing something I/O intensive before starting another app. And it makes no noise whatsoever.
Note: I wouldn't recommend SSDs unless you are prepared to make regular backups (you should be doing this anyway), and are willing & able to screw around with jumpers, firmwares and re-imaging. ;)
But give it another 12-18 months and SSDs will IMHO be the only drives worth buying -- they might be pricier than HDDs but they make the whole computing experience actually enjoyable. Mine literally saves me tens of minutes of waiting time each day.
The second amazing device is ye newfangled iPad. I'm far from an Apple fanboi, having never owned any Apple product (even our Apple ][e was a clone :). But I picked up the basic 16GB wi-fi model last week and its really a joy to use. I was always a bit hesitant about buying an iPhone as it is expensive and I couldn't see myself using a 3.5" screen all that much. The iPad is a different story though. I have multiple PCs at home but I don't really want to sit at a desk all day. Its nice to be able to read an e-book or watch a couple of episodes of Community in bed. Or if I want to quickly check something on the web its more convenient to use the iPad than go to my PC.
The main technical features that make it so convenient are its incredible battery life, and the beautiful screen. The battery life means I never actually turn it off - I'll press the power button to turn the screen off but when I next need to use it I press the one front facing button, slide to unlock, and I'm back in. No need to wait for a computer to come out of sleep or hibernation or worst of all, boot. And all the apps remember what state they were in, presumably because the device is never actually powered off. I had to charge it for the 2nd time ever after 5 days of a-few-hours-a-day usage. The beautiful screen comes into play as somehow text is easier to read on the iPad than on my 24" LCD.
The Apple lock-in with iTunes is a minor issue so far. I've been using Air Video to playback video over wi-fi, to avoid having to force my TV viewing through iTunes. I doubt I'll ever use it as a music player as its in-built speakers aren't really great for that, and its really too big to be used as a portable player. IMHO the size of the screen should tell you something about its purpose - use it for reading, browsing and watching. I bought the 16GB model with this view in mind -- use it as a network device, not as storage for music/photos.
I find the rage about its lack of Flash support overstated, and similarly with its current lack of multi-tasking. Its not a device I would try to use for my job so I'm not trying to read email, write a bunch of code whilst carrying on IRC and IM conversations and browsing the web. But it is a device that's fantastic for consuming content, wherever I choose to do that.