If you haven’t already done so, remember to grab the iPhone’s OS upgrade from iTunes. It’s got all sorts of goodies, including Arabic language support, and it’s totally free. For iPhones that are, say less official, you might want to hold off until jail breaking catches up. Otherwise, it could end up bricking your phone, making it totally unusable.
UPDATE: iPhone OS 3.0 Pwnage Tool has just been released. Thanks Mike.