I recently bought an HP ML110 G5 from Ebuyer because it was going very cheap (£220 for a dual core Xeon, 1GB RAM and 250GB hard disk). This box will be my new server, possibly for trying things out with, but maybe as a replacement for my Shuttle that currently runs VMware Server on OpenSUSE.
Unfortunately, the first attempt at installing ESXi failed with the message that no storage devices could be found. After some searching, I found that by changing the disk settings in the BIOS from "Auto" to "SATA" fixed the problem and the disk was found (full details here.
The installer again failed with the following error: "Unable to write image to the selected disk. This maybe caused by bad sectors on the device or another hardware problem."
One comment I read suggested the amount of memory could be a problem. As this is to be a VM server, I ordered another 4GB RAM (CT810056 4GB kit (2GBx2), 240-pin DIMM Upgrade for a HP - Compaq ProLiant ML110 G5 System) from Crucial and fitted it this morning.
ESXi installed without any problems. Now to install some VMs...