I recently bought my first netbook a Samsung N315, mainly so that I can have a computer with me when I am on holidays for web browsing, staying in touch with my projects and maybe doing some coding when I am feeling bored in the evenings.
The Samsung N315 has a nice look with rounded edges and a rubberized exterior. Specs are standard for current 10.1" netbooks: 1Gb ram, 1.66GHz n450 Atom cpu, 250Gb disk, wifi, bluetooth, 1024x600 display resolution, 3 USB ports, VGA out port, card reader, ethernet port and 1.3Mp webcam. It has a 'pebble' style keyboard which is comfortable enough to type on.

The machine came with Windows 7 Starter
preinstalled, but this deficiency was easily remedied
with the help of an Ubuntu 10.04 USB Startup Disk
(actually more stick than "disk"). Installation was
quick and without problems. Booting into Ubuntu takes
roughly 25 seconds. I installed the Ubuntu Netbook
Edition but after trying the interface out
I decided I prefer the normal Gnome interface
(configurable via
System->Administration->Login
Screen). To save some vertical space the Gnome
panels can be set to auto-hide.
All the hardware seems to be working great under
Ubuntu as far as I can tell. I had some slight concerns
before, having read that certain previous models had
some problems with wireless under Ubuntu (requiring the
windows driver with ndiswrapper to work),
but everything worked out of the box for me, probably
thanks to better support for netbook hardware in more
recent kernels. The battery seems to last around 3
hours with moderate use (browsing the web, installing
some programs, occasionally compiling something).
I only had two slight problems, one is that the
special function keys are not working and the other is
that I can't control the brightness of the display (not
just with the function keys, but the gnome brightness
applet does not seem to be working either). The display
setting was too bright for my liking but although I
haven't got the function keys working under Ubuntu yet,
they do work before I boot into the OS (when I am in
the BIOS settings for example). So I set the brightness
to a level I find comfortable before I booted into
Ubuntu. In order for the computer to preserve this
setting between reboots, you must change
'Brightness Mode Control' from
'Auto' to 'User Control' in
the BIOS settings, otherwise the brightness level will
be reset automatically on each reboot. But now that I
lowered the brightness I had another problem, namely
that the colors looked somewhat washed out. Usually on
my desktop I would set a higher contrast level to
compensate but I can't seem to find any way to control
the contrast for the netbook display. Fortunately there
is a utility called xgamma which does
exactly what I need (gamma and contrast are not exactly
the same thing, but it does what I needed), and by
setting something like xgamma -gamma 0.6 I
got enough contrast and the colors now look crisp. To
keep this setting between reboots you need to call
xgamma each time you start X, one easy way to do this
for people who don't want to tweak around too much is
to simply add it to Startup
Applications.
After some more googling I came across these scripts for fixing the above mentioned key and brightness problems, although by this time I got lazy so I haven't tried them out yet:
A lot has been said and written about the poor performance of netbooks, but I find that this netbook's performance is not bad for what I need it to do, and in any case it is not much worse than my 4 year old desktop (1Gb ram, Pentium D cpu), not to mention that it is much quieter (in fact it is completely silent, whereas my desktop on occasion sounds like something between a vacuum cleaner and a jetliner on takeoff).
For comparison GIMP starts in 6 seconds compared to 3 seconds on my desktop, but youtube videos seem smoother on the Samsung N315 than on my desktop. Also as a test I compiled one application I am currently working on: The application consists of 143 Java files and on my desktop the average build time is 5 seconds while on the netbook the average build time is 8 seconds (times are calculated loosely and unscientifically, basically I ran ant several times and after some initial fluctuation build times settled on the values given above). This may not be stellar performance, especially compared to the latest high end machines, but for me it is perfectly adequate and I find that netbooks have plenty of power for programming.