I flashed my n900 with Lehto's 125-825MHz kernel and set the smart reflex on in pmconfig. The results are quite amazing. I also
set the ignore nice load to 1

echo "1" > /sys/devices/system/cpu/cpu0/cpufreq/ondemand/ignore_nice_load

renice 1 `cat /syspart/applications/standby/background/tasks`
renice 1 `ps | grep modest | cut -c1-5`


Now my batterylife has increased threefold. Used to get max 16 hours if on idle most of the time now the battery holds for 24h with average usage and over 34h on idle with 1 hour of talking and 1hour opf surfing and some texting.