I'm warning you, though, any repairs to the NDSL requires a specialty (tri-wing) screwdriver, and the top screen needs a soldering iron!
If anyone tries out these instructions: could you give me a holler? (Comment, PM or email me at my user name at gmail dot com.) I want to get a sense of the success rate.
Pre-caution: This is a fairly wordy instructable. Most questions you might have, and problems you might run into are likely addressed in the body of the instructable (or within the comments). That means you need to read, and re-read carefully.
Actual intro!: Is the screen your Nintendo DS cracked? Don't throw it out, repair it. (And then sell it to help cover the cost of getting a new DS lite.) It is not expensive, nor all that difficult, to replace the screens on a Nintendo DS.
I found PowerGamingParts.com's guide to DS repair to be pretty useful, but I didn't need to disassemble the whole contraption, since I was replacing the top screen only. (Opening up the bottom half also requires a specialty screwdriver which I didn't have.)
I'm sure there's good directions for replacing the top screen without disassembling the bottom half, but I haven't found them. And since I'm feeling productive, I present to you documentation of what I did to replace the top screen.
Go poke around on the internet to find a source of replacement screens. A quick Google search turns up prices in the 40$ range, but Ebay has cheaper. Most screens will be "top/bottom" screens--they can be used to replace either, but the bottom screen does require an additional touch sensor overlay.
-Basic manual dexterity (Take a look at the photos to see the scale at which you'll be manipulating things)
-Small philips head screwdriver
Board (on which to place all your components)
Tape( to keep little parts from going missing)
Wood/plastic/something blocks (see steps 2 & 3 for photos of it in action)
These directions are reasonably devoid of dangerous actions, so if you break things or burn your house down, it's your own fault.
If your DS won't power on after repairs: it's probably an error related the the ribbon cables. I will repeat this litany often: go to step 2, look closely at the photos and the comments on the photos. Look at the comments on this instructable and see if anyone else had similar trouble, and what they did. Then go back and check your work! And if that still isn't solving the problem, you can message me and I'll make sympathetic noises but probably not have any additional information that isn't posted all over this instructable already. (Sorry?)