Originally Posted by mrblue

Also, you might try putting a little air in the flat tube, then squeezing it to force the air out through the puncture, to see where the hole is. This might help you find from where the puncture is originating (something on the rim or an object embedded in your tire). From there, you should be able to take a look at either your rim or tire and figure out what the cause of your series of flats might be.