I did wake to sleep when he was having 45 min naps at around 4 months and I followed the method as described in one of the posts on this forum.
Currently, I sneak quietly into his room about 5 minutes before he startles awake and put my hands on him (usually on his back b/c now he rolls to stomach to sleep). When he startles, his whole body jerks and wakes him up. I gently hold him in place and sshh him. If he sees me (I do not make eye contact) he starts to get excited (legs kicking, rolling over etc.). Then he starts to babble, laugh grabat my hands and basically start playing immediately. At this point he is pretty much up. If he IS on his stomach, his head is usually turned away from me and I can usually extend the nap by about 15 minutes with him fussing a bit. Even so, he'll still roll over look at me and wake up.
His schedule is still dependent on wake-up time, which varies. Anywhere between 6:30 and 8:00 a.m. I put him to bed at the same time every night and have used the same routine since he was 4 weeks old (for both bedtime and naptime), so I do not know why he wakes at different times. I tried waking him at 7 every day, but in doing so, I often deprive him of that extra hour of sleep (if he would have slept to 8:00). Anyway. Here is his schedule:
7:00-wake and bf
8:00-breakfast
10:00-10:30--nap
11:00-bf
12:00 - lunch
2:00-bf
2:30-3:00-nap
5:00-dinner
6:30--bath, pjs, books, bf
7:30--sleep
He usually wakes at 8:00 and shh/pat gets him back to sleep.
He also wakes again between 4:00-5:00 a.m. to eat. My pediatrician says it's ok since he was a preemie and could still need one night feed.
Finally, my son is a VERY high energy baby--always moving, even in his sleep. Tracy would say he is 50% spirited/50% angel.
Any advice is greatly appreciated.