I was installing Lion and my little kid pressed the power bottom while installation. Now I cant get the computer to start again. I have a boot usb with Lion in it and is not even working when booting from it...
You might have to format the drive and try again. If the Lion install did not complete, it's likely the OS is corrupt and theres no way to fix it. That's my suggestion, but if you don't back up wait for others to chime in with their opinion.
That will bring you to disc utility. Then google a guide to format a drive in Mac OS extended journaled. After thats done, you can try the lion recovery drive again.