C3-00 works with up to 32GB MicroSD Card | Phone/Device Issues and Features | Consumer forum

Just wanted to let people know that although it's advertised as 8GB max, I've used both a 16GB and a 32GB card with my C3-00 extensively without problems.

Remember that many MicroSD cards on ebay are fakes and can't reliably use all the space so only buy from a local store with a decent return policy and then max out the card with MP3s to test it in the phone!