I found this nice tool:
What is Lion Disk Maker?
Lion Disk Maker is a small application programmed with AppleScript that you can use with Mac OS X 10.6 or 10.7 to burn a DVD or build a bootable USB key from Mac OS X Lion’s Installation programm.
Download Lion DiskMaker 1.6.3 ( ZIP file, 800 KB).
http://blog.gete.net/lion-diskmaker-us/
