Lion Disc Maker is a free tool to make a bootable hard copy of Lion. With it, you can perform a new installation of Lion without the need to download it again from the Apple Mac App Store.
Lion Disk Maker creates a Lion installation file from the Lion DMG file that you download from the Mac App Store. All you need is a USB stick or external drive of at least 4GB and Lion Disk Maker creates a bootable version of Lion.
How does it work?
Lion Disk Maker uses Spotlight to automatically scan your Mac for the Lion-installation file. Unlike Apple's official Lion Recovery Disk Assistant all you need is the USB stick to restore Lion - no Internet connection is needed to re-download Lion unlike with Lion Recovery Disk Assistant.
What if I don't have my Lion DMG file anymore?
No problem. You can simply re-download it from the App Store. Simply go into purchase history and click on OS X Lion while holding the option key to start a new download of Lion. Since you've already paid for it once, you won't be charged for it again.
Lion Disk Maker is an excellent tool that creates a reliable bootable recovery disk for Lion. In contrast to Apple's solution, it's much better because it creates a hard copy of Lion which you can boot your Mac from.