Samsung NC10
One of my oldest devices, that helped me through my final year of university (for my dissertation) while also serving as a travel laptop in my younger years, is still operational in 2020 and still usable (for simple tasks). While it's age is showing, it can still be used for web browsing and email, even if video playback has become a problem.
History
For my dissertation I required a laptop that could run Linux while supporting an Atheros card and modified drivers. While the Asus Eee PC was my first choice (and it was used for the initial work) I needed something with more performance and more flexibility. Cue the NC10 with its small (but functional) design and good(ish) Linux support. A few modifications later and the device was perfect for my requirements.
Upgrades
The first part to be replaced was the wireless adapter (mini-PCIe) as an Atheros card was needed due to the modified driver requirement. Thankfully it was an easy change with very little effort. The next update was to the RAM to max it to 2GB, which was also easily sorted thanks to Crucial. Finally the HDD was replaced with a Crucial SSD to alleviate the performance issues that were being encountered when performing verbose logging as part of the dissertation project. Another painless change (albeit with an OS reinstall) which made a significant performance difference.
Hardware Limitations
Sadly (as with all old technology) there are hardware limitations that come with age. The 32-bit Atom N270 CPU wasn't known for great performance and when attempting to run large applications it showed (regardless of Linux distribution). The lack of 64-bit support also became an inhibitor for the device as the major Linux distributions dropped 32-bit x86 support (leaving the device on Ubuntu 18.04 once it was repurposed). While still able to browse the web/check email, video playback on the device suffers (due in part to the integrated Intel GPU and the lack of AVC/HEVC/VP8/VP9 hardware decoding). None of these limitations can be blamed on the device (as its an old device), its simply a shame to see a once usable platform run out of steam.
Current Status
The device is still functional and is updated once per month, though the updates are almost at an end given the ceasing of 32-bit Linux by most major OS vendors. It is still used for when a USB-to-Serial cable is required for terminal access as its small in size and quite rugged, with the battery still holding a decent charge after all this time.