T.,
When my son (who is now 21 months) was about the same age, I had problems with him waking much more than I wanted. I didn't want to let him just cry and leave him, so I compromised. I didn't leave his side, but I didn't take him out of his crib either. I played the same music for him at bedtime, so that became a cue for him to go to sleep. When he would wake up, I would go into his room and tell him that it was still night night time. I would lay him back down and start to rub his back to help him calm down. Sometimes he refused to let me lay him down, in which case I let him sit up or stand up and I rubbed his back. Sometimes he would stand and hold me, crying, until I could feel his little legs giving out from pure exhaustion. It was difficult and he was stobborn, sometimes I would do this for close to an hour. But I stood my ground as well and eventually he stopped waking up. He now sleeps great; in bed by 7:30 and up at 7, without waking in the middle of the night. I would say the process took about a week. It's a similar concept to letting them cry it out, but I didn't feel as bad b/c I didn't feel like I had abandoned him in bed. Eventually he learned that yes, momma is around, but no momma isn't going to take me out of bed.
Hope this helps and at least gives you an idea. Take care and good luck.