Reboot after Install
On Mac OS X 10.5 (Leopard) and 10.6 (Snow Leopard) the rEFIt boot menu does not appear on the first reboot after using the package installer. Just reboot the Mac again. (You don’t need to log in first.)
If the rEFIt menu does not appear on the second reboot, other software on your Mac may be interfering with the Mac OS X shutdown sequence. That can cause the rEFItBlesser startup item to not be run, and the Mac will boot straight into Mac OS X on the next boot. Further details are still under investigation.