You don't even have to have a traditional clothesline to take advantage of the natural resource. A folding drying rack is a great way to dry your diapers outdoors, especially if you have a small apartment balcony or deck. Get creative and hang a temporary clothesline between two trees outdoors or between the pillars that support your deck. You can even just lay your diapers across your outdoor chairs or table if you can't find a place to hang a line.
Just remember, don't leave your cloth diapers out in full sun and high temperatures too long. High outdoor temperatures can be just as harmful to your cloth diapers as high dryer heat can be. Check your diapers frequently and bring them inside once they are completely dry.