Magic Device Attunement( Complete Mage, p. 44)
You have a knack for activating familiar magic items.
Use Magic Device 1 ranks,
If you successfully activate an item with the Use Magic Device skill, you can take a free action to attune yourself to the item. For the next 24 hours, you can activate that item without making further Use Magic Device checks. You can attune yourself to only one item at a time. If you attune yourself to a second item, the previous attunement ends.