The historically reliable way to check for Linux support, without actually booting linux, is to count the number of special buttons and glossy gizmos on the notebook. The more of those, the worse the notebook.

Compaq and Sony in particular have been very poor for this. Dunno how much of that has bled off to HP since Compaq got swallowed.

On the plus side, with Intel chipsets pretty much taking over the entire notebook market, and Linux learning to parse ACPI macros, things are pretty good with a lot of machines these days.

Cheers