In my home Eberron campaign, I wanted to give out Dragonshards as big treasure items.  However, I found that none of my players would really get much benefit out of the few found in the Eberron player's guide.  I decided to put some universal effects on dragonshards to make them sought-after items by taking an item most PCs will have and expanding it out.  Here they are:

Eberron Shard of Expansive Power    Level 6+ Uncommon
This dragonshard shows its true power when you attack multiple foes at once.
Level 6    1,800 GP                      Level 26 1,125,000 GP
Level 16  45,000 GP
Wonderous Item (Dragonshard)
Property: You gain a +2 item bonus to damage rolls with area attacks using