you can do a regular oral thermometer. there are also those binki thermometers but my son wouldnt keep it in his mouth long enough. so we finally broke down and bought one that you just rolls across his forehead. i love it. its so fast
The paci thermometer's never worked for us either, the nipple was so long that my sons both gagged on them. My doctor suggested trying one of the forehead ones too, haven't yet but he says they're fast and reliable.
We used an under the arm one that we got when my son was in the nicu. I guess since he was used to it from the beginning he laid still for it. We now have an ear thermometer. It is quick and seems to work well.