We had a thread on this topic in here just a few days ago, don't know if you saw it or not.
Anyway...Yes, I believe you can be spiritual without being religious. In my view spiritual people subscribe to a higher power or the supernatural that affects their world view but do not live by any set of necessary dogma. Religion is taking these beliefs another step into the formation of dogma, practice of rituals (such as prayer or worship), attending gatherings (church), and the formation of ideologies.
So in a practical sense (let's take Christianity) you may have person A who believes in a creator, likes the teachings of Jesus, feels a certain joyful connection emotionally to others through love, etc. etc. but does not get concerned about theology, does not attend church, does not pray to anyone specific. This person I view as spiritual. Person B on the other hand believes in a specific creator (God) and his son Jesus, believes the Bible to hold truth and authority, attends a church and is involved in ministry, prays to God/Jesus, formulates a world view based around his/her beliefs. This person I view as religious.