Id like to chime in on the value of this thread as well. I've been skulking around watching these forums for years now. While SGIs necessarily stand still the rest of the computing world shifts around. What we would use them for in 1995 is different from 2005 is different from 2015.
I myself came here looking specifically for this type of information, with current ideas. My specific google search being 'what can I do with my 02 SGI in 2015'. Seeing something come up that has a historical legacy is helpful. Someone like myself from today might just as well admit that I mainly use my SGIs to sit on a shelf, and thats just not helpful. Instead I get to go and read years worth of ideas without flitting about.
Keep it going people!
At the moment it seems the consensus is having a unix reference, media serving, and music playing. Works for me!