Cory1492 has released an attempt at a dead pixel fixer program. This program will flash through several colors in an attempt to unstick pixels on the screen. here is what Cory1492 had to say:
I take no responsibility if this damages your NDS, some have had luck
using this type of a video on PSP and other LCD hardware, you may too.
Keep in mind, that some with the PSP pixel fix have made their screens
worse, as stressing the pixels may damage your screen further.
I ran it on my DS for a couple minutes and had no adverse effects, but my pixels
are all fine so I see no reason to stress the machine.
This is a file that may or may not help fix pixels on the nintendo DS.