Yesterday I bought a laptop for a friend, who also asked me to install Linux on it. Since she's not computer-savvy at all, I opted for an Ubuntu. I provide here a short description of the hardware and what to expect regarding compatibility for anyone about to buy one of these.

Hardware description
Model HP 530
Part No. GU322AA
CPU Intel(R) Core(TM) Duo CPU T2300 @ 1.66GHz (stepping 12) - 2 MiB cache
CPU flags fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc pni monitor est tm2 xtpr
Screen 330 mm x 250 mm viewable area, "glossy" wide-screen. 1280x800 pixels.
Video Intel Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller
Audio Intel 82801G (ICH7 Family) HDA
USB Intel 82801G (ICH7 Family) USB2 EHCI Controller
Ethernet Intel 82562ET/EZ/GT/GZ - PRO/100 VE (LOM) Ethernet Controller Mobile
WiFi Intel Corporation PRO/Wireless 3945ABG Network Connection
Optical media Optiarc DVD RW AD-7560A
Hard disk Fujitsu MHY2120BH, 112GiB, max UDMA/100

The only problems I had with the hardware were related to the sound card and the lid. The sound card had exactly the same problem as my Dell Inspiron 6400: it won't turn off the internal speakers when you plug something in the audio output jack. This is easily solved adding the following to /etc/modprobe.d/options:

options snd-hda-intel enable=yes model=laptop

The problem with the lid is that the screen didn't turn off when the lid closed. Just one time it did work, and stopped doing so after a reboot. Looking with acpi_listen, it seems that the acpi event isn't even generated. I don't know if this is a hardware or software problem.

Also, some not very nice things should be noted about it: it has no independent media buttons for volume, suspend, etc.; only the WiFi transmitter kill and the power button, the rest needed a key chord.

It has only two USB ports, which nowadays is incredibly few. No LEDs for hard dist, scroll lock or num lock. The audio jacks are on the front, which makes them very unsuitable for any straight plug. Although seldom used, it is nice to have the ability to turn the screen 180°, but this one can't do it.

Finally, the battery is tiny: only four cells amounting 2 Ah of capacity. The power consumption seems a little better than my Dell: running on batteries, with low brightness, an idle GNOME desktop gave a reading of 820mA. Watching a movie from optical media in full screen ranged from 1 A to 1.3 A depending on the spinning of the media and the codec. Burning a DVD at 2x took 1.15 A

The good

After installing a Ubuntu 7.10, almost everything Just Worked™. Of course it warned me about the non-free ipw3945 driver, but in seconds network-manager had connected to my home WLAN.

Network manager could be a little more smart and turn off the WiFi transmitter when it's disabled by the user, but I guess that's not only an Ubuntu problem :).

Most media keys worked out of the box, the WiFi kill switch worked OK, as did suspend to ram and to disk. Video acceleration and obligatory eye candy worked automatically. No problems either with burning a DVD, listening to music, watching a movie or connecting to my home network.

The external aspect is not bad, the screen looks good, and the touch pad is very nice: just a matrix of dots over a surface that doesn't show any other sign of being an input method.

In conclusion, it shows that it is a very cheap machine, but the drawbacks seem very few comparing to the good price.