XDA Developers wrote a tiny application that will make your life easier if you are not into registry editing or tweaking via Advanced Config and such just to get your SIM contacts to hide from your Contact list.
There are some times when you want your SIM contacts hidden from the Contact list (security, privacy of even annoyance) and there are times when you want them back in the list. SIMShowHide does just that: run it once to toggle the state (i.e.: if the current state is set to show SIM Contacts, running it once will hide SIM Contacts; if the current state is to hide SIM Contacts, running it once will show SIM Conctact). Download and install to device, run it and check Contacts; run SIMShowHide again and check Contacts to see the list toggled.