Note that once you have attached the Velcro, you would have to remove the Velcro to use the same sensor in a Nike+ ready shoe. Velcro is cheap, so it would be possible to simply replace it each time you watnted to switch. Or you could use 1 sensor for the Nike+ ready shoe and 1 for other shoes where you need to attach it with Velcro.
First, buy a good quality of Velcro. I purchased heavy-duty velcro for the job. The cost is a couple of dollars, and it can be found at an office supply store.
Trim a piece of smooth Velcro to attach to the tongue of the shoe. This piece can be larger than the other piece that you will attach the to sensor. You want to be able to position the sensor as desired on the tongue, so more velcro on the tongue is good.
Trim a smaller piece of the "male" rough Velcro to attach to the sensor. It should be small enough not to overlap the on/off switch on the sensor.
