Remounting /system in read/write mode, Froyo

I used this to remove unwanted application from my tablet advent vega, running Froyo. First, you need superuser installed on your system. Find a terminal emulator program on the Market. If everything ok, open the terminal emulator program and type:

#su

grant the emulator a superuser privilege, then continue:

#mount -o rw,remount /dev/block/mtdblock3 /system

this will remount your system partition in read/write mode. You can now navigate to system/app by:

#cd /system/app

and remove or copy any application you want to use as a system application. For example:

#rm Calendar.apk //removing the Calendar.apk

or:

#cp Cron.apk /system/app    //copy the Cron.apk to system/app

that's it, hope it help someone :)