I run NetBSD-Current (amd64) on my T61p; basically everything works as expected (including the graphics, i.e. non-accelerated). That is not a problem for me, as I triple-boot it (the others are W7/64 and, of course, OpenSolaris build 134).
Actually the latter runs best. NVidia acceleration out from the CD, all the keys work, suspend-resume without any problem, Java, AcroRead, even RealPlayer if you wish... W7 is as good as one can expect, but took some time to get all the drivers and the rest; NetBSD lacks the 3D NVidia stuff. I stay mostly under W7 (the VPN client I have to use is only Windows, although I have a spare VirtualBox m/c under OpenSolaris for that), use Crossbow/VirtualBox for network simulations under OpenSolaris, mostly pkgsrc under NetBSD (plus tracking -current).
It is the best laptop I've ever had, though. I wouldn't replace it even if it is almost three years old (especially with the maxed-out memory and a decent black scorpio disk).