I have a Dell Latitude D600. Pentium M 1.3GHz, 1GB RAM, 40GB HD, CDRW....and more.
I run Slackware Linux 9.1 on it. I have run it via VMware 4.0, and I have also run it perfectly fine natively. Here is a little something that you will for sure have to do if you load Slackware on your laptop.
When you first boot Slackware 9.1 the system will hang when PCMCIA cardmgr trys to start.
This was nicely documented though somewhere on the web as I have seen someone else have this problem. Oh yeah, some dude named Owen Cliffe listed some modifications to the /etc/pcmcia/config.opts file somewhere on the web. I booted the laptop off of a KNOPPIX 3.3 CD so I could modify the file. You could also use the Slackware boot CD and go in to modify this file too.
Here is what you need to change once you get to the /etc/pcmcia/ folder.
I like to use pico to edit this file so I do a:
....then change the following....
from include port 0x100-0x4ff, port 0x800-0x8ff, port 0xc00-0xcff
to include port 0x100-0x4ff,port 0xc00-0xcff
After this the laptop booted fine
Let me know if you have any huge issues (if you try Slack) because mine works flawlessly