Superboy moves the earth out of orbit:

http://img172.imageshack.us/img172/6650/precrisisfu4.jpg

This was already posted before, but only one panel. Here's the full page. He flies trillions of miles in seconds and goes to Alpha Centauri.

http://img19.imageshack.us/img19/6576/precrisis1hg4.jpg

Plays baseball with a moon:

http://img255.imageshack.us/img255/6232/precrisis2px4.jpg

Moves the earth with his breath, also states again how easily he can time travel.

http://img120.imageshack.us/img120/7474/precrisis4jf4.jpg

Superboy moves faster than light in the earth's atmosphere:

http://img233.imageshack.us/img233/7932/precrisisspeedch0.jpg