Now specifically a NetBSD question but I'm hopeful someone can 
help me with this.

I'd like to know if and how I can get lm sensor data from some 
machines here: one is actually running freeBSD and it's an older 
Gateway with a 440 LX motherboard, as far as I can recall (dmesg 
was long ago overwritten after 60 days of uptime). can you get 
dmesg-type info w/o rebooting?

here's what lmmon shows:

Motherboard Temp               Voltages

  255C / 491F / 528K        Vcore1:   +3.984V
                            Vcore2:   +3.984V
     Fan Speeds             + 3.3V:   +3.984V
                            + 5.0V:   +6.654V
     1:    0 rpm            +12.0V:  +15.938V
     2:    0 rpm            -12.0V:  -15.938V
     3:    0 rpm            - 5.0V:   -6.654V


another machine also running FreeBSD will return good information 
with 1 second updates.

  Motherboard Temp               Voltages

  31C / 87F / 304K          Vcore1:   +1.609V
                            Vcore2:   +3.359V
     Fan Speeds             + 3.3V:   +3.359V
                            + 5.0V:   +4.880V
     1:    0 rpm            +12.0V:  +12.188V
     2: 5532 rpm            -12.0V:   -1.375V
     3:    0 rpm            - 5.0V:   -1.383V

does any of this information help?

Timecounter "i8254"  frequency 1193182 Hz
CPU: AMD-K7(tm) Processor (704.94-MHz 686-class CPU)
   Origin = "AuthenticAMD"  Id = 0x612  Stepping = 2
 
Features=0x81f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,MMX>
   AMD Features=0xc0400000<AMIE,DSP,3DNow!>
real memory  = 268369920 (262080K bytes)
avail memory = 256622592 (250608K bytes)
Preloaded elf kernel "kernel" at 0xc0494000.

and last of all, can a late-model thinkpad run any lm stuff? I see 
dire warnings about it.