We bought a light up pooh bear at SpectroMagic - it saved our trip. We did actually have a very small flashlight, but it really didn't light up enough to make a difference. Pooh on the other hand glowed, and he had some pretty fiber optic lights that looked lovely.
Since he didn't work in the daylight, Katie was actually quite keen to go on dark rides after she got him, so that she could see him working.
One thing to note - we went through 4 in our week. The first one didn't work very well, so we swapped it straight away, then the batteries went flat in the next one, so we put fresh batterys in it, and it still wouldn't work, so I took it back and got another one, which had flat batterys in it (since you can't tell if they are on in the daylight, I think they get left on in the store and the batterys just run flat). The last one lasted us for about 4 days, and came home with us.
If it stops working I would just take it back to anyplace that sells them, and request a new one (assuming it's not just the batterys) - everywhere we went was happy to exchange it, but they did seem pathetically flimsy. I guess you are just supposed to use it at the parade and then throw it away.
Bev