Well perhaps is a stupid question or it was already answered (though I didn't find the topic) but is it possible to put N900 in to standby mode like e.g. desktop PC? I mean in the end this is practical a portable PC with linux OS?

You know in case where you don't want to completely turn off the device but you don't want to have it on either (to save battery, work in progress etc.) so that you can latter start it faster?

There is `Soft poweroff` mode in the /etc/systemui/systemui.xml - just uncomment the block containing Soft poweroff entry, and after restart (or killall systemui) it will show up in the power menu. However, it appears that on the N900 it just disconnects all the radios while keeping the device powered on, thus it doubles as the Offline mode.

Apart from that, I don't think there is a way to have it go to Standby/Hibernate mode - actually, a regular power-off is a Hibernate mode. You can put the device in real power-off by holding the power down button for 4-5 seconds, IIRC.

Not exactly what you want but I'm sure it'd help: N900 Hard Sleep Mode