MacRumors posted a quick guide about making an OS X Lion boot disc

Lion may be the first release of the Mac OS to be delivered as a digital download, but there has been a circulating method to burn the Lion download onto a bootable DVD. The process still works for the Golden Master version of Lion and is a pretty straightforward process for Mac users who are comfortable making their way around the Finder.

An email from Steve Jobs suggested the only way to perform a completely clean install of Lion was to first install Snow Leopard, then install Lion on top of that. That is a pain in the neck, to say the least. By burning your own Lion disc, you can painlessly do clean installs on all your machines.

  Make An OS X Lion Boot Disc