Spell slots as (not literal) "currency"

[Zaq]

What abilities are out there that let you spend spell slots (and I'm going to pretty much use that to interchangeably refer to uncast prepped spells and uncast spontaneous slots, unless otherwise noted) to do something other than cast a spell? I'm not referring to stuff like Archmage which has you permanently sacrifice the slot—I'm referring to stuff like Arcane Strike, which lets you feed spell slots into something that isn't a spell. I'm also not referring to spontaneous spell swapping (Clerics with Cures, Druids with SNA, Runestaves, etc.), though I guess Mage of the Arcane Order and Skypledged get an honorable mention for using spell slots to pay off spell debt.

Here's a very partial list to get the ball rolling, but I know that there's a ton more that I'm missing. I'll try to come back and update this with everyone else's suggestions. Not all of these are worth using, of course, but that's not necessarily the point.

Feats:

Arcane Strike (CWar): Spend spell slot(s) to add d4s of damage to weapon attack
Netherese Battle Curse (LEoF): Spend spell slot to add debuff to melee attack
Black Dragon Lineage (DrM): Spend spell slot to inflict fatigue/damage with touch
Blue Dragon Lineage (DrM): Spend spell slot to hurl orbs of lightning
Brass Dragon Lineage (DrM): Spend spell slot to force target to sleep
Bronze Dragon Lineage (DrM): Spend spell slot to force enemies to move
Copper Dragon Lineage (DrM): Spend spell slot to inflict Slowed (as the spell)
Gold Dragon Lineage (DrM): Spend spell slot to give allies bonus to saving throws
Green Dragon Lineage (DrM): Spend spell slot to inflict penalty on Will save
Red Dragon Lineage (DrM): Spend spell slot to create blast of flame
Silver Dragon Lineage (DrM): Spend spell slot to paralyze enemies
White Dragon Lineage (DrM): Spend spell slot to gain THP/cold resist


PrCs:

Archmage [Arcane Fire] (DMG): Spend spell slot to get ray of raw damage
Magical Trickster [Spontaneous Trickster] (CSc): Spend spell slot to recharge skill trick
Ultimate Magus [Augmented Casting] (CMag): Spend spell slot to apply metamagic to spell from other casting class


Classes/ACFs:

Druid [Spontaneous Rejuvenation] (PHB2): Spend spell slot to grant allies in area fast healing
Sorcerer [Divine Companion] (CChamp): Spend spell slot to heal self or prevent damage


Races:

Illumian [Hoonvaul] (RoD): Spend spontaneous spell slot to gain bonus to turning, turning damage, and smite damage
Illumian [Uurhoon] (RoD): Spend spontaneous spell slot to gain bonus to Ref saves and CL
Illumian [Vaulaesh] (RoD): Spend spontaneous spell slot to gain bonus to weapon damage and AC
Illumian [Vaulkrau] (RoD): Spend spontaneous spell slot to gain bonus to saving throw
Illumian [Vauluur] (RoD): Spend spontaneous spell slot to gain bonus to unarmed damage


There's more. There's a lot more. But I'm running low on time and want to open up the floor to the great hivemind of the Playground. What else can you think of that can directly use a spell slot for something other than casting a spell? Please cite your sources, if you could.

[ATHATH]

May I ask why you're doing this?

Isn't there an "Arcane Shield" ACF of some sort that lets you spend a spell slot as an immediate action to lessen damage?

Also, doesn't the Divine Companion ACF work with/for any class that has a familiar, not just a Sorcerer?

[Jormengand]

Magic item compendium's bracers of the entangling blast and bracers of the blast barrier use up spells, rather than technically spell slots, IIRC, but they are ultimately in the sphere of using a spell slot to do something which isn't casting a spell. The same is true of the energy transformation field, whichever book that's hidden away in, although it does also sorta cast spells.

[death390]

any reserve feat technically works for what your looking for. as long as you have the minimum level of a typed spell you can use a special standard action. these are still sacrifice-able but "reserved" in a sense.

[Anthrowhale]

Channel Charge (Lost Empires of Faerun) is the sub-epic version of Master Staff and Master Wand.

[gorfnab]

Here's a flavorful build that uses a number of the feats and abilities you've listed.

Karsite(ToM) Sorcerer 18

ACFs: Stalwart Sorcerer(CM), Battle Sorcerer(UA), Spell Shield(DgS), Dragonblood Sorcerer(RotD, lv4), Domain Access(CC), Dragonpacts (DM).

2 - LA, Medium Armor Proficiency, Martial Weapon proficiency, DR 5/Magic, SR 10+HD, Magic Drain(Sp, Cha-based), Spell Healing
3 - Stalwart, Battle Sorcerer, Spell Shield, Draconic Heritage, Draconic Breath
4 -
5 - Blue Dragon Lineage
6 - Dragonblood Sorcerer Sl-Ability(lv1, Nerveskitter), Dragonpact(lv2)
7 - Domain Access(CC)
8 - Obtain Familiar(CA), Sl-Ability(lv2, Wings of Cover), Dragonpact(lv3)
9 -
10- Sl-Ability(lv3, Wings of Cover), Dragonpact(lv4)
11- Improved Familiar(CW, Winter Wolf)
12- Sl-Ability(lv4, Celerity), Dragonpact(lv5)
13-
14- Arcane Strike, Sl-Ability(lv5, Arcane Fusion, CM), Dragonpact(lv6)
15-
16- Sl-Ability(lv6, Arcane Fusion), Dragonpact(lv7)
17- Spell-Linked Familiar
18- Sl-Ability(lv7, Arcane Fusion), Dragonpact(lv8)
19-
20- Martial Training(Shadow Stride)/Open, Sl-Ability(lv8, Greater Arcane Fusion), Dragonpact(lv9)

[Bayar]

Spare Hand has it's functions derived from the level of infusion you are willing to use to power it up.

[ATHATH]

The Spontaneous Affliction Druid ACF lets you spend spell slots to sicken humanoids within 30 ft. of you.

[BloodSnake'sCha]

There are some Draconic feats I will edit in a sec.

Edit:
Draconic Breath give you breath weapon with damage base on the apell level you use as payment.

I think there are more but I can't find them now. if I will find them I will edit them in.

[Mr Adventurer]

Isn't there an "Arcane Shield" ACF of some sort that lets you spend a spell slot as an immediate action to lessen damage?

Dungeonscape, I think. For Sorcerers.

[ATHATH]

The Ordained Champion PrC lets you spend spell slots for a few nifty things.

[daremetoidareyo]

jade pheonix mage

Dragonblood spell pacts