I've used lm_sensors briefly on a gentoo machine and it worked but coming back to that machine now and running sensors as root gves:
# sensors
Can't access procfs/sysfs file
Unable to find i2c bus information;
For 2.6 kernels, make sure you have mounted sysfs and libsensors
was compiled with sysfs support!
For older kernels, make sure you have done 'modprobe i2c-proc'!
I have lm_sensors 2.10.0 installed.

I think I compiled a new kernel but forgot the i2c stuff so I compiled it as modules now and loaded i2c_dev and i2c_amd8111 since I have an AMD 8111 chipset but when I type "sensors" I get the same result!

any ideas?