"Detect Disease" Cantrip

This spell is a variant of Detect Poison, and functions much the same way.

Detect Disease
School divination; Level cleric 0, druid 0, bard 1, ranger 1, sorcerer/wizard 0
Casting Time 1 standard action
Components V, S
Range close (25 f. + 5 f./2 levels)
Target one creature, one object, or a 5-ft. cube
Duration instantaneous
Saving Throw none; Spell resistance no
You determine whether a creature, object, or area has been infected with disease or is infectious. You can determine the exact type of disease with a DC 20 Wisdom check. A character with the Heal skill may try a DC 20 Heal check in stead. The spell can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it.

Update Paizo has come out with a first level Diagnose Disease spell in Ultimate Magic. However, it is not available to sorcerers and wizards, and why it is not a cantrip like Detect Poison is unclear, since it seems to do almost the same.

"Extinguish" Cantrip

This spell is a reversed form of the light cantrip intended to balance the field for dark dwellers. In most situations the dark dwellers do not need to create darkness, it is already there if they just turn out the lights. With this cantrip a first level sorcerer could be a big nuisance to a dungeon exploring party, who might have to employ two spell casters to have solid light, or resort to using torches etc. Also it establishes a reason to use light spells of a higher level like Daylight.

Extinguish
School abjuration; Level bard 0, cleric 0, druid 0, ranger 1, sorcerer/wizard 0
Casting Time 1 standard action
Components V, S
Range close (25 ft. + 5 ft./2 levels)
Target see description
Duration instantaneous
Saving Throw none; Spell resistance no
The spell can either extinguish all small flames within 20 ft radius; torches, lamps, and lanterns. Or extinguish one stronger source such as one non-magical campfire or person on fire, or one cantrip level light source.

Light and Darkness Rules

These are alternate and I think superior rules governing illumination. The goal is to have darkness be dangerous without being completely deadly to characters without darkvision, and still have Darkness spells be useful to dark dwellers.
I operate with three levels of illumination: Light (no concealment), Dim Light (concealment 20% mischance), and Darkness (total concealment 50% mischance).
I do not give "Bright Light" its own illumination category, because it is has the same concealment properties as Light, and that is what illumination is about. Whether the light is hurtful to a creature's eyes is a separate issue.
We all have a pretty clear idea of what happens when we light a torch in the dark, and the standard rules work fine for mundane light. A torch creates 20 feet radius of Light and an additional 20 feet of Dim Light. The problem occurs when we introduce magical light and darkness.

Darkness Spells

They look very similar to the standard versions, but have been changed slightly because the standard rules for how magical light and darkness interact were unbalanced. So here are the rules I recommend for magical light and darkness.

Darkness
School abjuration [darkness]; Level bard 2, cleric 2, sorcerer/wizard 2
Casting Time: 1 standard action
Components: V, M/DF (bat fur and a piece of coal)
Range: Touch or 25ft + 5ft/2lvl
Target: 20ft radius area
Duration: 1 min/level (D)
Saving Throw none; Spell resistance no
This spell has two uses, first it can causes darkness to spread out from object touched to a 20-foot radius. The area is impenetrable to mundane light, and lower level magic light create only shadowy illumination in its normal light radius and nothing beyond that. Daylight (spell) functions normally in the area of darkness, except it does not hurt light sensitive eyes within the area of the darkness spell. Darkvision functions normally.
Alternately Darkness can be used to dispel any one light spell of equal or lower spell level within 25ft + 5ft/2lvl.

Deeper Darkness
School abjuration [darkness]; Level cleric 3
Casting Time: 1 standard action
Components: V, M/DF (bat fur and a piece of coal)
Range: 25ft + 5ft/2lvl
Target: 60ft radius area
Duration 10 min/level (D)
Saving Throw none; Spell resistance no
This spell causes darkness to spread out from an object to a 60-foot radius. The area is impenetrable to mundane light, and low level magic light. Daylight (spell) creates only shadowy illumination in its normal light radius and nothing beyond that. Darkvision functions normally.
If targeted Deeper Darkness can be used to dispel any one light spell of equal or lower spell level.

NB I created a new cantrip: Extinguish

"Mold Earth" Cantrip

This cantrip is a little more useful than prestidigitation for creating tools, but suffers some limitations. It was originally created for an Earth Elemental sorcerer, but also fits well with the druids' elemental spells.

Mold Earth
School: Transmutation; Level: druid 0, sorceror/wizard 0
Components: V, S, F (see text)
Range: close (10 ft.)
Area of effect: 5 lbs of dirt
Duration: 10 minutes
Saving throw: none; spell resistance: no

This spell shapes up to 5 pounds of earth into one rigid object. The earth, dirt, or pebbles must be readily available within 10 feet of the caster, and cannot be part of a structure like a brick wall or adobe floor. The object shaped must be simple and cannot have movable or flexible parts, but otherwise acts as such an item for the duration of the spell. The item retains its earth property and appearance, and thus this spell cannot be used to shape anything that derives its function from being of a particular substance like food, jewelry, mirrors, floats etc. Examples of items that could be shaped and used: a step stool, a dagger, a club, a sling bullet, a jar. The object created has the hardness of stone (8) and one hit point per pound of mass. When the spell ends the object smolders back to dirt.

"Caltrop" Cantrip

This spell was developed for a halfling sorcerer, who needed it to cover his retreat, since he had a slower speed than most adversaries. As it turned out he never had an opportunity to use it before he was retired, so the spell has not been play tested.

Caltrop
School: Transmutation; Level: sorceror/wizard 0
Components: V, S, F (see text)
Range: close (25 ft. + 5 ft./2 levels)
Area of effect: 5 ft. square
Duration: 1 round + 1 rounnd/2 levels)
Saving throw: Reflex negates; spell resistance: no

This spell only works on an earth or stone surface. It makes caltrop spikes grow out of the ground in a 5 by 5 foot square area. Anyone noticing the caltrops before moving through the area (Perception DC 15) can pass through safely at half speed. Others fighting or moving through the area must make a reflex save to avoid stepping on a caltrop. Stepping on a caltrop immediately stops a charge or run, and causes a foot injury that reduces the victim's base speed to half. A DC 15 Heal check or other natural and magical healing restores the victim to full speed. The effects are not cumulative and target cannot be reduced to quarter speed from crossing through two caltrop fields, or spend several rounds fighting inside a caltrop field.