PPCGeeks - Rooting Phone

I've been thinking about rooting my new Moto Droid, but I want to know if there is any way for Verizon / Google / Motorola to know if it's been rooted?

I had an HTC Touch Pro for about a year and flashed many roms to it and eventually experienced hardware problems that required me to exchange it under warranty, so I am familiar with custom WM ROMs.

My concern is that if the screen/keyboard starts to malfunction then I want to be able to flash the ROM back to stock for a warranty return as was possible with Windows Mobile devices.

So, I guess the real question is, is it possible to reflash the rom to stock (reset the root account on the device) if I begin experiencing problems with something like the screen?