I have the Nike + the ipod and there was no way that I would buy the shoes that go with them (I love my asics and I'm an avid runner) The sensor will pick up anywhere on the shoe. I bought velcro from the fabric store and placed the sticky side (you buy it this way) onto the back of the sensor- the other half of the velcro I actually sewed into the tongue- facing up so that the sensor would slip under the laces but be held by the velcro, not just the laces. I positioned it pretty high up on the tongue so I don't have to untie the entire shoe to place the sensor. Anywho- this has worked great for me. Trying to insert it into your shoe is just too difficult and you could actually end up giving yourself an injury by messing with the actual arch supports of your shoe- it would be like running with a rock in your shoe!

The velcro is super cheap and the fabric store attendents will help you find what you need (I'm no sewing genius!)

Good luck!