What Are Some Inventive Ways to Use This?

So one of our engineers got a new computer (<RANT>which we won't get into, he actually bought a Dell XPS with an i7 he has no use for and a GTX 645, for $1000+, after I told him I'd build him a custom PC for $100 that was infinitely better, but anyways</RANT>) and he wants to do something with his old PC...

I don't have all the specs of it with me right now, he brought me a few pages of irrelevant stuff and this is what I recall from it... but in general...

CPU: 1st gen i5

MOBO: yes it has one :)

RAM: 8GB

STORAGE: 3x 1TB HDD

GPU: Radeon 4xxx

PSU: lord knows...

So the unimaginative thing to do would be make it into a home server... he's got a couple ipads so throw in a wifi card and it could be useful that way... I was also thinking of a HTPC media box for his home theater...

and other more imaginative uses you guys can think up?

He generally does need media storage... he does use CAD... otherwise it was just a web-browsing machine before...

Other than what you mentioned, you could use it for a PFsense router, or as a home automation hub.  But honestly, either a file server or a htpc would probably be more useful to him.  Sometimes usefulness needs to trump creativity.