I've joined udpcast and Gentoo's tftpboot Linux environment with lzop, Busybox, raidtools, etc. to make a solution for booting Sun Sparc machines on the network and using Udpcast to do the usual business of cloning disks and partitions.
There is a guide (and related downloads/links) here:
http://www.artistic.ca/dteed/tftpboot-udpcast.htm
This might be useful for those who have wanted to 'boot net' a Sun sparc and use Udpcast from there.
Enjoy...
--Donald Teed