I have my cels insured via the Collectors' Insurance Agency.
You can check them out at collectinsure.com.  You can get
$60,000 of coverage for as little as $200 a year...a much
better deal than renter's or homeowner's insurance (both of 
which WON'T cover your cels).  They have policies for 
collectors and dealers as well as collectors who are dealers.
They know their market well and it's very easy to sign up
(they don't require you to itemize your collection).