The screen on my storm is cracked all the way across. So far performance is not affected. Will it later?

Wirelessly posted (overwhelmingly stressed)

I would say as with any damage to anything eventually it mat affect the device

Is it the screen or the plastic cover over the screen?
if its the cover, you could replace that yourself

I did not know it had a plastic cover.

Where can I get info on how to do this?

If you go to Cellular Nationwide Network - 3G, Sony, Panasonic, LG, SonyEricsson, Nokia, Tools, BlackBerry,, they have videos and the parts you will need.
Pretty affordable. I have bought quite a few parts form them.