Is there any way to make the caller ID picture larger?
there is no way to adjust the size of the pic. pics can be attached to contacts either by editing the contact or through the gallery.
contacts that match entries in facebook will automatically download their profile pic. however, because of speed and bandwidth issues, facebook is set up to download the smallest profile pic image, which will make the image appear grainy or blocky when you receive a call.
The easiest way I've found is to assign pictures using gmail on your computer, its easier to manipulate pics on a PC for me, I use a photo editor to cut the image and resize. Pics assigned to contact while using gmail will be auto synced to your phone.