Earlier this week I installed my first OpenWRT firmware on my Linksys WRT54G Version 2.2.  It was factory fresh and had firmware version 3.03.1.  I was not successful in setting boot_wait using the methods given in the OpenWRT documentation (http://wiki.openwrt.org/OpenWrtDocs/Installing), but note that I did not downgrade the firmware as recommended in this documentation.  Note particularly that I couldn't get the ping_times exploit work using the perl script referenced in the documentation. However, I was able to make a shell script that uses a similar exploit (lsysexec.sh found at http://www.kurokatta.org/doc/wrt54g-hax0ring) work just fine to set boot_wait with firmware 3.03.1.