Skill-based save DCs?

[ILM]

I'm looking for effects like the Bard's fascinate, where you make a skill check which becomes the target's save DC. So far I have the following:
- fascinate, Bard 1/Celebrant of Sharess 1, perform
- sanctuary, Celebrant of Sharess 7, perform
- Song of sorrow, Dirgesinger 1, and song of horror, Dirgesinger 4, perform (it's not actually a skill check but the DC is 10 + ranks in Perform)

[AnonymousPepper]

There's Truenamers.

On the opposite side, Warblades can base their saves off a skill check (Diamond Mind maneuvers, keyed off Concentration).

[ZamielVanWeber]

Swordsages also get Diamond Mind maneuvers and a few more skill points (but no int synergy)

[Chronos]

Of course, anything that sets a save DC equal to a skill check is going to be horribly overpowered, since skills scale at one point per level, while most save DCs and saves scale at one point per two levels, plus it's a lot easier to get big bonuses to skills than to saves or save DCs (there's no second-level spell that gives +20 to a save, for instance).

Which is really annoying, because sometimes you'd really like to tie the skill system together with the saving throw system. One possibility I've toyed with is to set a save DC at half of the result of a skill check, but then that throws the ability score component out of whack.

[Zaq]

There's Truenamers.

Not true, sorry. Your Truespeak check has nothing to do with the save DC. Save DCs for utterances are 10 + 1/2 Truenamer level + CHA. Doesn't matter whether you barely meet the Truespeak DC or whether you crush it by 50 points, the save DC is the same.

Anyway, Intimidate forms its own (kinda wonky) save DC, and so most things that are based on Intimidate (like the Intimidating Strike feat from PHB2) set save DCs based on skill results.