Janie Bowthorpe (of Stop the Thyroid Madness fame) recommends a mercury thermometer to take your temperatures, claiming more accuracy for them than digital thermometers. It would cost me about $30 to buy a mercury thermometer. Is it that much more accurate than a digital thermometer that it's worth the cost?

Old, but still on the front page and figured someone might benefit from the information at some point.

You can pick up a "veterinary" mercury thermometer (that, interestingly enough, has a prominent mark at 98.6 ºF when the average temp in animals is 102.5 ºF...) for far less than $30.

Example

http://www.parentsconnect.com/paren...hermometer.html

Says they're as accurate as the mercury ones.

You can stick your digital thermometer in a glass of ice water to check it's accuracy, it should read really close to 32 degrees. Get a digital one and check it now and then.