My experience as a working mom was that the easiest and most effective method is what you have already discovered -just let him sleep with you. Since you work full time, he is likely missing you and sleeping with you at nite can go a long way towards making up for that time away during the day. At this age, babies cry for a reason and it sure sounds like he just wants to be near mom and dad. If you don't want him in your bed, you might try putting his crib right next to your bed - sometimes that's close enough. For my second son, he would start out in his crib in our room and then the first time he would wake up to nurse at nite, I'd just bring him to bed with us and we all slept well for the rest of the nite.