Karma and I have been discussing this idea on and off for a few days now, and we both think it would be a great help to designers if there was a way to test out clothes for different types of tinies without having to own all the tiny avatars under the sun. We thought of two possible ways to go about this.
1) Dummy avies could be made and placed in Silica Cubicle. They'd just stand there, no copy/mod/move/etc., and provide a reference for sizing things. The downside to this would be the inability to actually precisely fit things for wear, but it would still help a lot.
2) A "designer's avie pack" could be released with the popular tinies in it, but these tinies would be covered in some really obnoxious texture so they couldn't be worn as regular avatars - like bright red DEMO text on a yellow background or something. This avie pack could be sold for a price considerably lower than buying all the normal functional avies.
Any combination of these ideas would work, too. For instance, rather than being placed in Silica, the dummies could be sold in a pack to designers. Or the dummies could be placed but the designer pack in #2 could be offered as well. You get the idea.
What do you guys think? I'm dropping this idea in Extrovirtual's suggestion box, but I wanted to place it here, too, to see if other designers like this idea.