Basically, I just bought a pile of these things, and all I've gotta do print out my character portraits and paste 'em on. The really remarkable bit? If I run out of glass bits, I can just scrub off the portraits and reuse them.
Anyway, we've been using these things in Lost Worlds and Secret Histories to represent the PCs on my simple little hand-drawn maps. Range and positioning in Spirit of the Century is handled in a really fuzzy way, using general "zones" instead of any kind of exact measurements, so playing it fast-and-loose totally works. I think I might get a magnetic whiteboard to draw maps on, and maybe actually add magnets to the character tokens. That could be pretty convenient.
Oh, one other thing: SotC frequently features hordes of minor antagonists ("minions") who really don't rate their own tokens, and would really start to crowd the map if they got 'em. So, instead of inch-and-a-half glass bits with pictures, we've been using those little "glass stones" people use to keep track of point pools in other games.