Alright, to explain the name of this thread:
The feat Inlindl School from DotU allows you to sacrifice your Shield bonus to AC for an untyped bonus on attack rolls equal to 1/2 that amount. Sadly, it only works for light weapons, so it can't be used to boost power attack.
I posted a build a while back, namely:
Crusader 6/Suel Arcanomach 3/Abjurant Champion 5/Paragnostic Apostle 1/Argent Savant 3/Crusader +2
With this feat, he can sacrifice the +13 bonus he gets from the Shield spell to get a +6 to hit. Not too good, but it isn't shabby, either.
On the non-caster front, a Fighter could qualify for this feat at 1st level (the prerequisites are Int 13, Combat Expertise, Shield Proficiency, Weapon Finesse), and use it with a Tower Shield, for a +2 to hit, that scales up to a +4 at higher levels. If, however, we went into Sanctified One of Wee Jas for 5 levels, and then grabbed 5 levels of Sanctified One of Wee Jas + 3 levels in Uncanny Trickster, we'd be getting a +16 bonus from a +5 Tower Shield.
That's a +8 to hit. If we were crazy, and went Something 5/SOoWJ 5/Legacy Champion 10, we'd get a Tower Shield with a +22 bonus, for +11 to hit.
Now, what other ways do you know of to increase shield bonuses? This is a pretty nice feat if you want to make a sword-and-board character, anyway.