A month ago I was able to successfully install a working OSX 10.5.8 install on my Dell Inspiron 1501 for a more enjoyable development experience. Having a bunch of scripting languages, sdks, gnu tools, all wrapped in a sexy UI makes for a lovely time. I finally took the time to document said process. Be forewarned however that dual-booting with a Linux distribution or Windows could make the network interfaces have issues.
I essentially followed this guide - Installation of OS X 10.5.8 - to get a working system, but there are a few things left out. All the files that are mentioned (which you will need) in the above tutorial I made local copies which you can also obtain here: osx-inspiron-1501_drivers.zip.
I found the easiest way to get dual booting working properly with OSX and Windows XP was to 1) format the HDD with gparted (can be found as an independent bootable system or a componenet of many Linux distros) - create a HFS+ and NTFS partition, 2) install Windows XP, and then 3) install OSX from your iDeneb disc (so that the Chameleon bootloader is installed properly).
What the tutorial fails to state is that: you should not start the Kext Helper application by double clicking, but should instead drag the codec text dump (Sigmatel9200.text) onto the application icon, which will then start the application and patch the system. See Linux codec dump for SigmaTel 9200 (How to do?) on the insanelymac.com forum for more information on creating your own codec dump (probably not necessary as I found out the hard way).
The Mac OSX Quartz (graphics layer) does not work with the Inspiron 1501 hardware. Thus, several noteable visual applications do not work properly, namely VLC. Instead of installing VLC, I was able to play many of the same files with Perian installed (in conjunction with QuickTime).