I've put my initial release of !LDR up at:
http://the.earth.li/pub/e3/notldr-0.0.1.tar.gz
It'll compile up to a ldr.img file that you can put in /dev/mtd3 and loads 128K from /dev/mtd1 to 11f00000 and calls it ie will just load u-boot and no more.
In addition the u-boot diff I'm currently using myself is at:
http://the.earth.li/pub/e3/delta-20060518.diff
It'll automatically boot a kernel from /dev/mtd0 if no key is pressed with 30s of loading, which is plenty of time to interrupt it but still allows an unattended boot.
No prebuilts of either of these yet. I have a cunning plan to do some sort of installer that you'll load the basics of over pbltool which will then pull in everything else off a USB memory stick, as well as backing up a virgin E3. Dunno how achievable it is nor when I'll find the time.
J.