Here's a blog entry about setting up Ubuntu Server on a Dell PowerEdge 2950
Read it here
For a project I'm involved with, we're setting up a shiny new server to handle hosting of lots (and lots) of Drupal sites in a shared hosting environment. We were able to pick up a decently speced Dell PowerEdge 2950 at a really good price. Dell wanted a tonne of cash to pre-install RedHat on the box. Um, no thanks. So, our friendly neighbourhood colocation provider installed Ubuntu Server on the box for me (I'm about 1000 km from the server, so couldn't actually do the physical install myself). The PowerEdge is a 2xdual core Xeon, similarly speced as the new Xeon XServes, but not as nicely packaged. This one requires 2U of rackspace, where the XServe is shoehorned into a single 1U slot.