I have Slackware 12.2 running on two laptops. One is an HP DV9999US (DV9000 series). The other is an Acer Aspire 5050 (the model with a single-core Turion at 2GHz.).
Slackware 12.2 has some improvements in support for wireless adapters over previous versions.
Slackware works better on the HP DV9999US. I was able to get the wireless adapter working with the "madwifi" package. The wireless LED doesn't work but the laptop has a switch that is mechanical so there is no confusion about whether wireless is on. The sound card driver supports most of the features of the laptop except for the external mic input. I did have to use a Linuxant modem driver to get the soft modem working. I had to adjust some of the Synaptics configuration defaults to work correctly with corner button tapping.
On the Acer 5050 Linux works better than either Vista or Windows XP. Both Vista and XP pause for many seconds randomly. Linux doesn't have that problem. I've discovered there are different versions of the Acer 5050 and I have one of the worst (lowest performance). I never did get the soft modem to work. I bought a $30 PCMCIA card modem and that works. To get the sound card functions working such as the microphone and headphone speaker shutoff I had to edit the source files for the driver. I had to use ndiswrapper to get the wireless working. The wireless light doesn't work and the switch is momentary. It's difficult to tell if the wireless is turned on.
The three typical laptop issues that people have with Linux are the sound, wireless and soft modems. Neither HP nor Acer had anything helpful on their site for Linux users.
I really went about this the wrong way because I didn't buy a laptop based on how well the hardware was supported by Linux. In both cases I got a laptop on sale, and Linux was a secondary consideration. I really encourage anyone wanting Linux on a laptop to research the Linux support for the hardware before buying. Be careful about part number differences too. I discovered that my Acer Aspire 5050 is totally different than some other Acer Aspire 5050 laptops. The dash number after the 5050 makes a big difference.