I'm on my 2nd one (no fault of the first), both were Acer Aspire Ones. I had the 8.9" blue one and loved it, so when an extremely good deal appeared (even up trade) for the newer 10" in red I jumped on it.
Here's the thing though, and you really need to understand this in order to appreciate a net book. It's not a replacement for owning a "real" computer, yes some people they can use it just fine I am aware of that but the vast majority who see a $250 price and say "Wow, that's cheap and small and I can replace my XXXXX with it" are setting themselves up for disappointment.
The only reason these machines even exist is because hardware moved so much faster than software over the last 5 years that 5-10 year old hardware is still "Good enough" for most tasks.
The current generation of (non-ion based) netbooks have severe deficiencies in video and to a lesser extent processor power. They often stutter playing back flash video, and you have little hope of playing back a 720p video stream. If you play web-based flash games, that's not a big drawback but if you do anything more video intensive than that you will be hurting.
Speaking of web-based flash games, the standard netbook resolution on 8.9 and 10.1" displays is 1024x600. Many web-based flash games do not adjust well to a screen smaller than Nx768, and you may run into issues.
Intel Atom (netbook) processors are single core chips designed for low power consumption. They are remarkable for their performance/watt for x86 processor but they are nonetheless "weak sauce" compared to even the cheapest current generation desktop/laptop processors. They are not dual core, they are however hyper-threaded. They have limited pipeline and small amounts of cache. They run at low bus speeds. They are limited to 2GB of ram. They are limited to old technology chipsets.
All that is a lot of negative, and the sad part is I'm not trying to talk anyone out of one! I'm just trying to keep perspectives in check.
I LOVE my Netbook! I use it EVERY day. It sees way more use than my workstation at home.
Just keep in mind what it's good for. They're awesome for surfing the web, blog posting, forums reading, flashlight sniping on CPFMP and eBay, and there are some really fun "old" games (Re-Volt is a great RC-Car racer with 'real' physics that was abandoned to public domain and works great on netbooks, Google it you won't be sorry.)
They're low power consumption, my Aspire One draws less than 1A at 12VDC through an inverter, and a great companion for my Amateur Radio hobby. The fact that it runs WinXP is great as most of the software for Amateur Radio is just finally now being updated to work with XP. They're great to take with you out into the field, the availability of 6, 9, and 12(!!) cell batteries means you can run them for well over a full day with no outside power whatsoever.
Combine one with a usb cellular card or a bluetooth/usb teather to your cellphone and you have an extremely powerful portable Internet station.
My AspireOne 10.1 has a really nice display (the 8.9 was not nearly as nice) bright enough that I usually run it several steps below it's max brightness.
The device itself is small enough that it fits in the bag I carry to work daily, and it also easily fits in most of my other grab bags for different tasks.
Anyway, I think that netbooks are great, and I hope they don't disappear. I'm looking forward to the new tablet (totally keyboardless) versions that are supposed to be coming out before the end of this year.
