Affects Version/s: Minecraft 14w34d, Minecraft 1.8-pre1
Fix Version/s: None
Setting a /clear @a command on a setblock clock will result in the inventory of the player being cleared, but then all new items put into their inventory remain visible until interacted with, whereupon they disappear.
1. Make a setblock clock: "/setblock ~ ~1 ~ air" and "/setblock ~ ~-1 ~ redstone_block"
2. Put a command block with /clear @a on the clock.
3. Place new items into your inventory
4. Place down the block/splash the potion/etc. (ie right click with the item)
5. Item disappears and any placed blocks using that item appears for a split second and disappears.