Linden Realms, the popular quest game in Second Life has a flaw. Maybe more than one depending on who you speak with, but I can think of only one: The crystals often rez within the bounding boxes of plants thus making the crystals inaccessible.
If the plants were changed to "Phantom" (no physical presence) then a game player could run through them to collect crystals that, as things are now, are un-collectable. This would also increase the number of crystals available over a given time period (pink ones return from harvest faster than yellow ones do, yellow crystals return faster than orange ones, etc., the most valuable green and blue ones taking the longest) and also increase the number of really valuable crystals at any given time. Whenever I run a particular section I see this sad green crystal worth L$1 at trade in (equal to finding 50 pink crystals). If this plant was Phantom I'd know to come back to this spot every hour after grabbing one as crystals always re-rez on the same spots.