My 23 month old is still waking 1-3 times a night. He did a brief period of sleeping through for a month, which was pure bliss, then we went away for a weekend, and he hasn't been the same since. He was a 2 hourly waker for the most part of his first 14 months of life though.
I wish I could offer some suggestions to help. We just tried everything we could think of. Massage, baths before bed, or earlier in the day, we bought a sleep sheep which did help a bit, downloaded a CD of Metallica baby tunes, played the ipod in his room, have the air con on have it off, Amby hammock, formula for bed time as opposed to breastfeeds, reading as many books as i could find to explain something or anything at all for that matter.
goodluck, hope your little one discovers the joys of sleeping through the night a bit longer, very soon