As I was scrolling through my collection of Second Life outfits, I realized I was hopelessly lost as to what was what. While I try to rename folders so they are more meaningful than "Charlotte in Blue", I still can't remember what the outfits actually look like. So I thought...what if you could have an arbitrary image assigned to a folder and the viewer or server or whatever would convert it into a thumbnail? The idea being you could visually see what the outfit looked like in its folder. It might even be helpful for builds or full avatar folders.
However, I'd only want to see this feature if it didn't appreciably affect viewer performance and if it could be turned off and on, or made into a different "view" on Inventory. Thinking further, if you could name an image (not always possible though) with a convention like thumb_myimage, the viewer would know to make it the thumbnail for the folder.
Anyway, I made a JIRA new feature request for it here (vote for it if you like the idea):
https://jira.secondlife.com/browse/VWR-27168
And here's a link to my topic in the Second Life forums if you'd like to discuss this there:
http://community.secondlife.com/t5/Second-Life-Viewer/New-feature-Thumbnail-images-for-folders/td-p/1167227