I have a transparent pocket in a handlebar pack. I can operate the N900 fine when it's in the pocket, but the problem is that when someone calls, the proximity sensor doesn't see through the plastic and won't activate the screen. Is there a way to disable the "pocket protection"?

Also normally I have the "lock automatically" setting on, so that a blank screen cannot be activated via touch. I can change this from the settings, but I'd prefer to do it from my desktop. Is there a way to change settings from command line or via dbus, so I could make a small app for that (combined with a solution to the first problem)?

The proximity sensor relys on detecting a reflection of IR it transmits, so what you could do is find a material which absorbs rather than reflects this light, in a quick search I found it registers as open when covered with some black string and a slightly glossy black leaflet, it will be a bit trial and error finding something that works becuase something that absorbs visible light might reflect IR light. You can check the state of the sensor with the command open = uncovered, closed = covered.

No way to set a flag somewhere to just force the proximity sensor "position" in software? I'll look into fabrics too, but so far haven't found anything that works.