An interesting feat:
Extra Divine Power
Type: General
Source: Dragon #343
You can use one of your divine granted abilities more often.
Prerequisite: A divinely granted class ability with a set number of uses per day.
Benefit: Choose a class ability you have from a class that grants divine spells and has a set number of uses per day, such as a shugenja's sense elements or a spirit shaman's spirit form. You may not select an ability granted by a domain. You may use the chosen ability two more times per day.
Special: You may gain this feat more than once. Its effects do not stack. Each time you take the feat, it applies to a different class ability.
The aspirant cleric variant (Dragon 311, p49) has a spontaneous casting ability that can be used to cast
any cleric spell, but it can only be used once per day, plus an additional time per day for each four cleric levels. (Actually, the class skips granting another use at 20th level for some reason.) Seems like a pretty tempting target for the feat.