T-Mobile G1 screen protector on cracked screen?

The screen of my T-Mobile G1 has had a big spider web shaped crack for over a month now. I've been using the phone with a makeshift cover of plastic wrap and scotch tape over the crack and it has actually worked fine with no further damage. I'm trying to avoid buying a new device until my next uprgade. If I buy a screen protector and use that instead, will it work for a few months? What protector is best?