FJ, I was going to suggest the teething tablets too, they're fantastic.
About $14 for a little packet, you get about 125 tablets in it.
They are homeopathic so completely natural. You place 2 or 3 tablets on their gums and they disolve instantly. So many parents swore by them when I worked in a day care centre, and i've used them on DD, and my nephews.

With the panadol syringe, if you hold it in the back of their mouth and then leave it between their teeth for a little bit they can't close their mouth to spit it out and have to swallow it!