Yes, they're still around!
I've got a bunch of old SGI'sin my office: an Origin 200 Server, an Octane,5 O2's and an Indigo2 at home.. They're all inactive except one that's still being used as a file server running Samba for our Model Shop. Since our IT dept. doesn't allow unpassworded accounts and Samba does, it's been used since we went to Active Directory 10-12 years ago.
As to why, it's a pain to log in to a passworded account on our old NT3.51 based CNC mill (and there's no storage space on the mill itself), so the O2 is used to store NC files from multiple machinists in a central location. It's been running for years.
From a power consumption perspective I suppose we could get a low power mini-PC and run Samba on Linux on it and save some electricity, but I couldn't bear to throw them out: we spent over $250,000 for all the SGI's (and a couple of nearly useless Sun Sparc 10's).. now they're boat anchors..
When we were still using them for other things, I ran WindowMaker ("NeXTStep" look-alike) as my desktop window manager and found it much better than SGI's 4D desktop. There was lots of useful open source software on SGI's freeware site and gcc ran pretty nicely on it for anything else you might have wanted to install.
I've told my colleagues that I'm going toclose my "SGI Museum" soon and they'll head to the recycling center. I could use the office space :-)
Interesting to note that the only Mips R4400 based computer still actively being used around here is my son's old Nintendo N64 :-)
In Reply to Doug Pogatetz:
I Remember the "SGI's". Very nice for their day. $ Though. Are they still around?