When the phone is connected to the computer by USB cable and you choose mass storage media or pc suit mode + charging, can anyone write a script that makes the USB button in status menu pressable and enable a new mode where you can disconnect the usb and keep only charging. You can use this if you wanna keep charging through your computer and you wanna open MyDocs or play music/videos which you can't while the computer is using your phone as mass storage but you don't wanna unplug then plug your phone again and not choosing both options (mass storage - pc suit)
So, is such idea helpful and doable ?

When the dialog that appears to choose between mass storage mode or pc suite mode, just click the blurred empty area outside the dialog box and voila!

i'm not talking about that at all ammyt
after transferring stuff from your computer and you wanna use your phone's music-video-MyDocs but still wanna charge it, thats my point

Well unplug the USB Cable and attach it again?

read the 4th line ?

Not a direct solution, but try using WinSCP or any other similar program to access your N900's files over wifi. This will allow you to copy files over through WinSCP, while still using your n900 normally. Though just be careful of possible interactions (if any).

I believe if you install Mad Developer (from MADDE) it lets you change the connected mode without unplugging the cable. Otherwise I think you could perhaps rmmod from xterm. Not sure if any other step must happen during that.

Isn't mad developer only shows your IP address ? but even if its not its just strange that nokia made the USB button in the status menu unpressable

in Mad Developer click the "USB Networking" button and then you should see new buttons that let you change between mass storage or Unix/Windows networking mode. I believe if it's mounted in storage mode and you choose one of the networking modes, it might do what you wanted. The PC will see it as a modem, but you can just ignore that for this purpose.

I haven't tried it so maybe there's some other catch.

I would advise against this - the reason for this is to prevent against data corruption.