Gross Motor Skills and Educational Toys
At around 3 month, you will eventually see your child bring up his arms across his chest so that he can touch each other hand. The movement of the arms together comes from this skill where as the touching or playing of hand/fingers is a fine motor skill.
When you see your child use gross motor skills you can encourage him to practice them more by giving him activities that require the same motions. Help him expand his skills in little steps. Too much may be more then he is ready for. At around 18 months he may be ready to use the gross and fine motor skills necessary to use a shape sorter box. This is a great educational toy to use to help advance many different skills.
The link below should help in finding a good educational toy that can help develop gross motor skills along with others.