This invoker Class Acts article allows invokers to strengthen the connection with their respective deity by picking up Awaken God Fragment, a nifty paragon feat that gives you a few constant benefits in addition to augmenting your encounter and daily prayers.
The constant benefits are about what I'd expect for a typical heroic feat: +2 to a pair of skills, allow allies to reroll saves against specific conditions, or even a single skill bonus plus something else (like resist cold temps as if you were always under an Endure Elements ritual). I think the shittiest one is fragment of Sehanine, which gives you a +2 feat bonus to Stealth. Yawn.
On the other hand, the encounter-based benefits can be kind of nice. Fragment of Corellon lets you or an adjacent ally teleport when you use an encounter/daily prayer, while fragment of Avandra lets an ally make a free save (two against certain conditions). I think one of the sweetest ones is fragment of Ioun, which lets you reroll any damage dice once.
There's one fragment per "core" deity, but none of the evil ones.