Oman is a friendly and welcoming place for children. For younger kids, beachcombing, sandcastle building and paddling in shallow water make Oman a dream destination. That said, there are few specifically designed amenities for children, except for a park with swings in most town centres and fun zones in each city's main mall. Refer to Lonely Planet's Travel with Children for general details about travelling with children.
If you ask for an infant's 'cot', you will most likely get given a full size adult mattress as this is the meaning of the word in the local use of English. Specific cots for children are less widely available, particularly outside Muscat and if you ask for a child's bed in all but the top-end hotels, you'll most likely be given an adult-sized mattress.
High chairs are available in top-end restaurants and fast-food chains in Muscat. Kids are generally welcomed in the family section of all restaurants.
Safety seats for children under the age of four are now mandatory, although you wouldn't think it, given the number of local kids who ride on the driver's lap or with head out of the sunroof. Safety seats should be booked in advance with your car hire.
Nappy-changing facilities are available in hotels and malls in the big cities, but few (if any) amenities exist in the interior. Disposable nappies and milk formula can be bought in most supermarkets throughout the country.