My Cousins T-Mobile phone also none as the g1 is frozen how de we unfreeze it?

it all started when he said i could play with his phone and i was bored so did the smoke screen its the app that makes the phone foggy and you clear it with your fingers and you can blow in where the charger goes and it make more fog but anyways i was playing with it and then the phone froze how do i unfreeze it?? plz i need help!!!!!!!! :(