Enhancement bonus question

[Human Paragon 3]

Does enhancement bonus on armor or shields apply to your touch AC?

[Jasdoif]

No. The enhancement bonus applies to the armor or shield's armor or shield bonus; which does not contribute to your touch AC.

[JackMage666]

However, in Lords of Madness, there is a feat that allows you to add your Shield AC against Touch Attacks. Shield Ward, I think.

[Roderick_BR]

There's the Shield Ward feat on Player's Handbook 2 that makes your shield's bonus count against touch attack, and a feat for psyonics in the Races of Stone to spend power points to "energize" your armor or shield so they count against touch attacks.
Other than that, shields and armors are ignored against touch attacks, as Jasdoif said, even with magic bonuses.

[Keld Denar]

If you have the ghost touch armor enchantment, you get to add the armors entire armor bonus to your touch AC vs incorporial touch attacks. This means the normal armor bonus, plus the enhancement bonus. If you had ghost touch armor and a ghost touch shield, yes, they would both increase your touch AC (one is armor enhancement, the other is shield enhancement) toward incorporial touch attacks (but not regular touch attacks).

[Shhalahr Windrider]

If you have the ghost touch armor enchantment, you get to add the armors entire armor bonus to your touch AC vs incorporial touch attacks.

But despite the similar names incorporeal touch attacks and "normal" touch attacks are two very different things. It is more than just principle; the distinction has a number of concrete effects. So it's best not to confuse the two.