Next issue after updating my T-Mobile UK phone. Most ROMs are available for mainly US keyboard layout ( qwerty ), but unluckily my keyboard layout is UK ( qwertz ) – after updating, it started working funny. Whenever I am typing Z, it was printing Y and vice -versa . So, I started to check /system folder for the solution. The file with keyboard character type placed under /system/user/keychars/ and the name of the file is trout-keypad-v3.kcm.bin . So, searched and found that keyboard layout and then replaced the present file of USqwerty keypad with it to make it qwertz layout. Bydefault, /system folder is read-only. So, follow the procedure written below, before that copy keyboard layout file after downloading it from following URL
http://kewlshare.com/dl/33e5be5db589/UKkeypad.zip.html
1) Power of the mobile.
2) If you followed my previous post for rooting G1, you already have cyanogen recovery installed on your phone. So, press Home + Power to start your phone in recovery mode.
3) Choose last option, “Go to Console”
4) type following
mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system
cd /system/usr/keychars/
dd if=/sdcard/trout-keypad-v3.kcm.bin of=trout-keypad-v3.kcm.bin
reboot
And voila … you are done 
keypad will work as it was before rooting/putting US roms in it.
More laterz buddies.
Next time will be with step-by-step tutorial to making partitions on your MicroSD card including swap, which is suggested by most ROMs for Google G1.