Work progresses. I've tidied up most of the edges and more caretakers are on board. We now have a sky background which may have some smaller spheres in it. I am worried that as I continue to edit the main sphere there may be some degradation of the overall quality BUT... I did a scaled test print and the whole sphere, as it stands, will print out well at 30" x 20". My print was gloss and I think a matt finish may be better. At this size you can easily read all the names of the caretakers, which, by the way, at the moment are:-
Snygyst, gill288, cdr256, GOHEMI, Arcenciels, gypsy_woman, nightwatchman, shadow_fire, ScillyGirl5, jesaminesoo, LestatTheVamp, Wildjasmin, BluefireFox, number69, possoms, Pharlap5987, remerc12, Pinkey93,SunMist, RainCat, Teriluu, tlight, distantstar, mermaid17, angel52294, mbolduc, kaileybear, rascalmom, Nunnutaja, Martin2011, Emerald123, Bexa, iarih and TPeers.

I googled Mega-Sphere and it seems to crop up in dozens of games. Not sure if this matters, but I could rename it. Any suggestions? "The Sum of All Spheres" springs to mind. It's a bit inaccurate but you could make a film out of it. :)